So, firstly bitsat is the exams given to join  any of the 3 campus of bits i.e bits pilani, bits hyderabad and bits goa. So according to last year taking the max. Marks to qualify bits, here is the cutoff of pits pilani-

You can refer to BITSAT website

There are previous year cutoffs available there 

So the cutoff may vary this year but not much difference

The link 

https://www.bitsadmission.com/cutoffscores2018.aspx

This is last year cutoff 

Atleast 250 is required for chemical in Hyderabad