Hey DIY 

Here ’s  The Formula To Find Rank From Your Percentile.

100- Your Percentile = Your all india Rank/ Total Students  appeared * 100

Or In Easy Way You Can Say 

Your Rank = ( 100 - Percentile )  *. Total Students  appeared / 100

Is The Way You Can Calculate Your. Rank From Given Percentile

I Hope It Helps 

Good Luck 

Dear candidate,

percentile rank refers to the percentage of scores that are equal to or less than a given score. 

The percentile rank formula is: R = P / 100 (N + 1). R represents the rank order of the score. P represents the percentile rank. N represents the number of scores in the distribution.

Hope the answer is helpful.

All the best!