In India, the system of patent is managed by the Patents Act, 1970 (Act No.39 of 1970) as amended by the Patents (Amendment) Act, 2005 and the Patents Rules, 2003. The Patent Rules are regularly amended in concord with the changing environment. The most recent amendments in the Rules have been done in 2019.
As the patent is not a global concept, it’s a territorial right confined to a specific territory with protection for a limited period of time i.e., 20 years from the date of filing of patent application. In the case of National Phase Application filing under Patent Cooperation Treaty (PCT), the 20 years term of patent will be from the International filing date prescribed under the PCT application or PCT Filing in India.

To understand the registration process in depth at Indian PTO, we have to focus on following things:
1. Who can apply for a patent?
2. System of applying/filing of patent application.
3. Types of patent applications.
4. Various Forms prescribed under the Patent Rules, 2003.
5. Timeline prescribed for each step under the Patent Rules, 2003.
6. Lifecycle of a patent application under registration process.

Who can apply for a Patent?
A patent application can only be filed either by the true and first inventor of an invention or his Assignee (Either alone or jointly with any other person(s)) or a legal representative of any deceased person.

System of applying/filing of Patent Application (Patent Registration in Delhi)
In India, there are two modes of filing of a patent application i.e., Offline and Online. In case of online mode applicant can file patent applications through comprehensive online filing system available at https://ipindiaonline.gov.in/epatentfiling/goForLogin/doLogin.
India has four patent offices located at Kolkata, Mumbai, Chennai and New Delhi. Each office has a separate territorial jurisdiction which depends normally where the applicant/first mentioned applicant resides/has domicile/has place of business/has origin of invention. In case of foreign applicants, it depends on the address for service in India given by such applicant.