Yes, you can get a CSE branch at 319 marks in class 12th but it is tough to get into top colleges unless you don't have any category like SEBC, ST etc.You have to do the choice filling very wisely if you are only selecting the CSE branch in the college. If you will fill only CSE in top colleges then it may be possible that no college will be allotted in counseling so keep this in mind and choose the colleges carefully. I will also suggest you opt for the IT branch also, as its syllabus is similar to Computer science and also does not require much high merit like CSE.