Hello Dhruvil

Actually, you cannot because you don't have the accurate data that how many students appeared in the examination and how many of them scored better than you. Let me give you an example of how to calculates percentile.

Suppose in an exam 1000 students appeared

You scored 60/100

500 students scored more than you and rest scored less than you. Therefore 50 % of the students scored less than you this means your percentile is 50 %. Percentile is relative marking which tells you your rank.