Hello, 

As soon as you have cleared BITSAT your score will be the criteria for your branch in the college. 

But,  along with this they are having a minimum criteria which everyone must follow that, one's aggregate score in PCM/PCB must be at least 75% along with 60% in each PCM/PCB respectively. 

So,  if your 12 grades fall under the above criteria and you have qualified BITSAT, then only you are eligible for B. Tech admissions in BITS. 

Hope this will help. 

Thanks.