The general eligibility criteria for applying  BCA course is you should complete your 12 th examination or equivalent with minimum 50% in total and also having mathematics as a subject in qualifying exam. But some institutions may also drop minimum % marks to get admission in BCA course. While some colleges  admit on basis of 12th but some reputed institutions conduct ENTRANCE exam for admission of BCA exam.

The admission and eligibility criteria vary college and university wise so please share where do you want t get admission into.