Birla Institute of Technology, Mesra

Hey Buddy!
I'll not give you false hopes.
It is too difficult to get a seat at BIT, Mesra in engineering course in regard to the details that you have provided.
The thing is that 85% in CBSE board (Would like you to confirm your board), degrades your chances.
Though, I would recommend you to pursue any other course/college and keep looking for chances of
getting admission in BIT Mesra during "SPOT & EXTRA SPOT ROUND'.
Also, BIT Mesra has an institutional round. You should try that.
But, Keep in mind that you have a less chance to grab a seat in BIT Mesra engineering courses.
Though, I don't have any idea about admission in other graduate courses of the college.