Hello

It would be difficult to calculate the marks on the basis of percentile. Expected rank can be calculated using the formula mentioned below:

100 - your total percentile score is the percentage  of people ahead of you. 869010 are the number of candidates appeared for Jan exam.

So rank formula is (100 - your total score) X 869010 /100.

According to the formula, probable rank is around 191182.

It should be noted that if the number of candidates for April exam increased to 1200000 then your final rank shall be (100 - your total score) X 1200000/100.

Good Luck!