BITSAT is an examination of a total mark of 450. Since the competition is quite high and the cuttoff depends on:
Difficulty level of examination
Total number of candidates  appearing the exam
Highest Score of the examination
It is quite difficult to guess the cuttoff marks.But if we check previous year cuttoff 
BITS PILANI CAMPUS:378
BITS HYDERABAD CAMPUS:334
BITS GOA CAMPUS:347

So, you will have to score atleast more than 350 to get Computer science branch in Bits
If you need aany more information refer to the link provided below:
https://engineering.careers360.com/articles/bitsat-cutoff

Hello Shiva!

BITSAT is an entrance exam conducted for admission in all the three campus of BITS in INDIA called BITS PILANI, BITS HYDERABAD, BITS GOA.

The cutoff for CSE in all the three BITS campuses goes over 340. The safer score will be anything above it. By above I mean you must set your target around 400.

ALL THE BEST!

the minimum marks for cs is 350 

Well cut off has been 370+ in last few years....but I would suggest you to target 390+ as a safe score