Hi Tarun,
BCA is a three year full time course divided into 6 semesters. People who  are interested in Computers or want to build their career in the field of Information Technology can opt for this course.

General Eligiblity Criteria for BCA is 10+2 from recognized Institute with one of these subjects:- Maths, Information Technology, Computer Science.
But some  reputed colleges provide you BCA without mathematics also. Every College has its own Criteria for Eligiblity and its selection process. It totally depends on the college or University you opt for.

Hope it helps:)