Hello there...

First of all congratulations to you for scoring well in the exam .

I would like to tell you that percentile doesn't depends directly on the marks that you've scored in the exam in a particular shift.

In every shift different number of students give exams .Also it depends upon the difficulty level of questions in a particular shift .

So you may get relatively lower percentile with more marks and relatively higher with lower marks in two different shifts.

Thanks...

I hope it'll be helpful..