JEE mains percentile or rank has nothing to do with the Scholarship. To avail Scholarship in Amritha you need to attend their own Entrance Exam, AEEE.

You can only get the Scholarship if you apply for the campus of  your Native State.

For less than 1000 ranks you may get 90% scholarship. Upto 2000 , possibility for 50% scholarships . Upto 4000, possibility for 25% scholarships.