Hey  Rahul



You can check the percentile of not only bihar board,  but of any board by going through the following link :



https://engineering.careers360.com/articles/top-20-percentile-cutoff-of-class-12-boards-for-iit-admission



otherwise,  the percentiles for bihar board is as follows:



Year 2018



GEN 293



OBC-NCL -287



SC -279



ST -284



PwD -279









Hope it helps!