Patent prosecution begins at the stage where applications are made to the patent office for grant of patent. The process of grant of patent is a time consuming process which may require negotiations with patent examiners. Patent prosecution is a comprehensive process which undertakes heavy examination before granting a patent. It also involves certain post grant procedures for instance amendments to specification after grant of patent.
The three essentially required criteria for patents are-
- Novelty and Non-obvious or inventive step- A patent cant be granted unless the idea is novel, it may include improvements in prior inventions. However, the idea should be original. It should neither be copied from an already granted patent nor should it be available in public domain by any kind of publication. The subject matter can either be a product or a process for which patent application is filled.
- Industrial application- The invention should be such that it facilitates utility. It is imperative to hold an industrial utility which makes it fit for the purpose of increasing efficiency of industrial processes.
- Not attract section 3 and 4 of Patents Act, 1970- A patent can not be granted for any product which is disqualified from patent protection. Section 3 mentions a comprehensive list of things which are disqualified from patent protection, section 4 further puts restrictions on inventions relating to atomic energy.
STAGES OF PATENT PROSECUTION
The stages of patent prosecution can be broadly classified into pre grant and post grant stages. The stages which takes place before grant of patent is called pre-grant stage and the prosecution process which takes place after grant of patent is called post grant stage. It can also be classified as pre-examination, examination and post examination stage.
i) Filing, specification and publication- After drafting a patent Specification, one can begin with patent application, a Patent Specification can be provisional or complete, Patent Specification basically specifies the details of the invention written in prescribed technical language which may or maynot be with inventor’s claim. Based on these specifications an application may be provisional or complete. 
India has four Patent offices based in Kolkata, Delhi, Chennai and Mumbai with different jurisdiction, the jurisdiction depends upon Applicant’s place of residence, domicile place of business; place of origin of invention or for a foreign applicant, the address for service in India.
The provisional or complete specification is filed in form 2 while Patent Application is filled in Form -1. The date on which an application is filled is called priority
After expiry of 18 months from date of patent filing or date of priority( generally priority date and filling date is used interchangeably, priority is basically used to establish novelty or non obviousness in relation to other art, priority date may precede filling date) whichever is earlier, right after the patent application is completed the patent is published in official gazette of India.
To expedite* the process Form-9 can be filed.
Examination of patent application is conducted by IPO to determine if the patent applied for satisfies all the formality clauses, is novel, consists of an inventive step and has an industrial application.
All the documents and formalities are reviewed by the examiners, who undertake a global patentability search and prior art search.
However, like patent publication, patent examination is not an automatic process; it requires an application for examination.
Requests for Patent Examination can be filed within 48 months from the priority date. On failure of submission of application it is assumed that the patent application has been withdrawn.
Getting a grant for a patent generally takes 5-7 years in India, however, by way of National IPR Policy, a faster route is taken and the time is reduced to 18 months by Patent (Amendment) Rules, 2016. This is called expedited patent examination.
Under Patent Cooperation Treaty (PCT), National Phase application, the time period of 31 months is granted for examination application. However, the expedited application has restricted applicants for example when an applicant is a start up, small entity, has choosen India as Internat Searching Authority (ISA) or as an International Preliminary Examining Authority( IPEA).
iv) issuing examinantion report, response to the Examination report and further proceedings.
Once the authorities complete the initial examination process a first examination report (FER) is issued to the applicant highlighting the objections in the application. The applicant is bound to submit a response to the FER within 6 months which can further be increased by a maximum of 3 months upon a request. During the examination state in case of any inadequacy or inability of the invention to satisfy the essential features of a patent like novelty, non - obviousness or any other document unavailability shall be mentioned in the examination report which is given to the applicant. An applicant is required to submit the response to the examination report in which the applicant may present arguments in his favor explaining the intricacies, he may further present modifications to claim, drawings or documents keeping in mind the scope of original application. Upon satisfaction with the arguments and modifications by the applicant the examiner may grant patent to the applicant however, if the examiner stands dissatisfied he may proceed with a second examination report or hearing notice.
An office action response mechanism is the process in which the applicant presents claims and defense to the questions raised by the examiner, the applicant is required to submit all the documents and evidence in support of his claim. When the examiner is not satisfied with the response submitted by the applicant or it is possible that new objections emerge in such cases the applicant is called for a hearing; however, the applicant must be informed 10 days prior notice. The case is presented by the applicant or applicant's agent before the controller in charge of the application.
v) Patent issuance
After all the required formalities and submission of documents upon completion of all the requirements under this act, the examiner, upon satisfaction that all the due process is followed, may grant a patent.
After receiving a satisfactory response from the applicant, the examiner can grant the patent, and in certain cases, a hearing may be necessary. Following the response to the First Examination Report (FER), the examiner might issue additional office actions, and the applicant needs to respond promptly for the patent to move towards approval.
The validity of a patent in India is 20 years from the filing date for both regular and convention patent applications. For PCT national phase patent applications, it's 20 years from the filing of the international PCT application. Post-grant, renewal fees are due from the third year to the twentieth year, and they must be paid before each relevant year expires. The pending annuity at the grant date must be paid within three months of the grant.
Failure to pay the renewal fee on time leads to patent revocation. During the period between revocation and restoration, the patent holder cannot pursue any legal action for infringement of the patented invention.
vi) Patent opposition Support
A patent opposition mechanism which is available in many countries allows third parties to oppose the claim of patent. With a restriction of time period, such objections can be considered only within stipulated time. The opposition can only be considered if it falls under the grounds specified under section 25(1) &(2). India provides for a pre grant opposition and post grant opposition, a pre grant opposition can be made after the publication stage and post grant opposition is made after the patent is granted, post grant opposition can also attract provisions of infringement against the applicant.
- Pre-Grant Opposition Certainly at the examination stage the process takes place between examiner and applicant but once the application is published any third party can raise an objection for the grant of patent before the examiner. According to section 25(1) of the Patents Act, any person can file an opposition to the patent applied for. Arguments and evidence are represented before the examiner by both the parties.
According to Rule 55 of Patent Rules 2003 opposition needs to be filed in form 7A. The opposition party should add a statement of case with evidence, further they can also make a request for a hearing.
Appeal against pre-grant opposition- section 117A specificies the sections against which no appeal lie section 25(1) is placed under the list.
However, anonymously filed opposition are discouraged because at times a bogus opposition is filed to delay the grant process. In Dhaval Diyora v UOI, these anonymous oppositions also called benami opposition are discouraged by the court.
- Post Grant Opposition- sec 25(2) of the Patents Act specifies post grant oppositions, this should be filed within one year of date of publication, even after the patent is granted an interested person may apply for opposition to the patent.
This can not be filed by any person but only by an interested person. The infringement proceedings can not be initiated in the pre grant stage however it can be initiated in this stage because the patent is not merely in an application stage but has been granted by this time.
Grounds for Opposition under section 25(1) and sec 25(2)-
(a) When the Patentee wrongfully obtained the invention.
(b) When the invention was published before the patent claim's priority date.
(c) When there is another patent claim, filed later but with an earlier priority date, covers the same invention.
(d) When an invention is publicly known or used in India before the patent claim's priority date.
(e) When the invention applied for patent is obvious and lacks inventive step is not patentable.
(f) The subject of the claim isn't patentable under the act.
(g) The patent description is unclear, if it doesn’t sufficiently describes the invention or the method of performance.
(h) Failure to disclose required information or providing false information.
(i) In the case of a convention application, the patent application wasn't made within 12 months from the first application in a convention country.
(j) Incorrect disclosure of the source and geographical origin of biological material.
(k) when there is any anticipation based on knowledge within local or indigenous communities.
vii) Pre-Grant and Post-Grant Amendments
Sec 57 and 59 of the Patent Act provides the provision of pre-grant and post-grant amendment respectively.
The applicant by rights mentioned in section 57 and 59 may address the controller raising request for amendments in the patent application or specification by providing the details of the amendment proposed and the reasons associated with the proposal.The statement proposed to the controller in charge of the application should contain all the particulars and reasons of the amendment
The amendment must not go beyond the scope of original claim and specification. It is in the discretion of the controller to accept or reject the request based on the adequacy of information and requirement. Even when the controller approves the request he may add certain conditions to it.
Under section 59 following are the permissible amendments-
An amendment made by disclaimer, corrections, clarification or explanations; for incorporation of actual facts; whose effect does not broaden the scope of specification and an amendment which falls within the scope of unamended claim.
Make an appeal
The applicant may file an application to the controller if he has any objections to the controller within one month of such order of the controller.
Within three months of the order date, an appeal of the Controller's judgment on both pre-grant opposition and post-grant opposition may be made to the Intellectual Property Appellate Board (IPAB). On the other hand, an appeal to the High Court and not the IPAB is available in the event that the Controller grants a patent subsequent to rejecting a pre-grant opposition.
IPAB now stands abolished by GOI by passing Tribunals Reforms (Rationalization and Conditions of service) Ordinance, 2021. The reason stated for abolishing five appellate tribunals was blamed on inefficiency of the tribunals, now the cases are shifted and handled by respective high courts, any case which earlier fell under the jurisdiction of IPAB is now dealt by the high court which has the jurisdiction over the area.
 Intepat,Fast Track / Expedited Patent Examination in India, https://www.intepat.com/blog/expedited-patent-examination-india/,
 Sec 25(1) and sec 25(2), Indian Patent Act, 1970