hi,

see to become eligible for admission to b.tech course in Computer science or any others stream of engineering, you must have studied physics, chemistry and mathematics as a mandatory subject. qualifying marks criteria may differ college to college.

since you have interest in computer science I recommend to take admission in BCA course , then you should go for MCA course after completing bca. the work opportunity and technology is similar with CSE and you would get the opportunity to work in computer science domain.