Hi Anjali,

for any exam, Percentile Score shows the percentage of candidates who have scored equal to or below a particular percentile in an exam. ... Also the marks between the lowest and highest scores are also converted to percentile. It is comparative, based on the performances of others who have given the same exam.

Percentile =(total no. Of people behind you/total candidates)*100

Refer to the following link for cut offs:

https://www.quora.com/What-is-the-cutoff-of-UGAT

All the best!