To get admission in BITS, even the Hyderabad campus  you need to score atleast 260 marks at the minimum to secure the chemical or civil engineering branch . BITS PILANI cutoff goes as high as 290 and above. To be eligible in VIT vellore, you need to get a rank less than 20,000 to be able eligible for admission in Vellore campus 

For getting admission to BITSAT, you need to score 290+ in their entrance exam . There are a total of 150 questions and each question carries 3 marks. One mark is deducted for wrong answers. There will also be an additional 12 questions if you attempt all the 150 questions without skipping. 

For VIT, there are a total of 125 questions each having 125 marks and no negative marking. You can surely get a college if you score 70+. 

Hope this helped.