There is no such percentage criteria to apply for PMSSS scholarship and also no application fee is charged for the application. You should have passed your HSC/10+3 diploma passed if you are applying for PMSSS .
But one thing you should know is that if you are declared pass you can apply but the allotment of the college purely depends on the following factors:-
1. Your 12th marks and merit rank you get in the merit list published by Aicte.
2. No, of candidates applying for the scholarship.
3. Your category i.e SC, ST, SEBC or OPEN
Hope thus helped ..