Hello Akash

We can not calculate marks on base of the percentile score.

Percentile score is a relative score depending upon the number of students who score more than you and total number of students not on the marks out of total marks you got.

Let's take 2 cases

You score 250 in ist and 300 in second

But number of total students is same and number of students who score more than you in both the case is same than your percentile will be same.

If you have any other query; you are always welcome.

So good luck.