Vishal, for being eligible for BCA in BIT Mesra, you should have completed your 12th with a minimum aggregate of 50%. It is 50% for General Category and 45% for SC,ST,PWD. You also need the same aggregate in your 10th. You should have studied English and any one among Mathematics, Computer Science, Information Practise as your subjects. Even if you do not have Mathematics but you have Computer Science or Information Practise, you are eligible. Please visit their official page at: https://www.bitmesra.ac.in/UploadedDocuments/admadmission/files/BBA%20n%20BCA%202019%20-%20Eligibility%20Criteria.pdf for more information.