The eligibility criteria depends from college to college. It is different for different colleges.
But In general, for B.Tech. and B.Sc. courses in Computer Science, you need to have mathematics as one of the subjects in class 12th.
Hope this answer helps!
Well very rarely any college will allow a biology stream student to go for computer science because usually mathematics stream students go for this but if you have both bio and maths, then you can. Some private colleges allow you to select any course irrespective of your high school subjects like Ashoka university in haryana.
I hope my answer helps.
All the best.