Hello,

If you are saying that your scores in Physics, Chemistry and Maths are 98, 80 and 70 respectively, then you are getting an aggregate of 82.6 percentage in these three subjects. The boards criteria for admission in BITS is to get an aggregate of 75 percentage in Physics, Chemistry and Maths subjects. Also, you must obtain at least 60 marks in each of Physics, Chemistry and Maths subjects. 

Hope this helps.