Section 6(3) reads as follows: A registration certificate granted under sub-section (2) shall be valid for such period as may be requested by the applicant and specified therein subject to a maximum period of ten years. An application for the renewal of a registration certificate shall be submitted online not less than thirty days before the date of expiry of the registration certificate or of the renewed registration certificate, as the case may be, and shall be accompanied by such fees, and the renewed registration certificate shall be in such form, as may be prescribed.
Max period is 10 years after which renewal is needed.
Individual state acts will have to be read to get an answer to the query. 19th January 2019 From India, Pune