Section 135

Convention applications

(1) Without prejudice to the provisions contained in section 6, where a person has made an application for a patent in respect of an invention in a convention country (hereinafter referred to as the "basic application"), and that person or the legal representative or assignee of that person makes an application under this Act for a patent within twelve months after the date on which the basic application was made, the priority date of a claim of the complete specification, being a claim based on matter disclosed in the basic application, is the date of making of the basic application.
Explanation.—Where applications have been made for similar protection in respect of an invention in two or more convention countries, the period of twelve months referred to in this sub-section shall be reckoned from the date on which the earlier or earliest of the said applications was made.

(2) Where applications for protection have been made in one or more convention countries in respect of two or more inventions which are cognate or of which one is a modification of another, a single convention application may, subject to the provisions contained in section 10, be made in respect of those inventions at any time within twelve months from the date of the earliest of the said applications for protection:
Provided that the fee payable on the making of any such application shall be the same as if separate applications have been made in respect of each of the said inventions, and the requirements of clause (b) of sub-section (1) of section 136 shall, in the case of any such application, apply separately to the applications for protection in respect of each of the said inventions.

(3) In case of an application filed under the Patent Cooperation Treaty designating India and claiming priority from a previously filed application in India, the provisions of sub-sections (1) and (2) shall apply as if the previously filed application were the basic application:
Provided that a request for examination under section 11B shall be made only for one of the applications filed in India.