First of all, you will have to meet below eligibility criteria -
Candidate must have passed class 12th or senior secondary examination with at least 50% marks including English.
The 12th examination must be passed/Appearing with mathematics as a compulsory subject.
The minimum age limit is 17 years and the maximum age varies between 22-25 years.
Some institutes/universities admit student on merit basis. The merit is prepared on the basis of candidates performance in the qualifying examination (12th).

Note :- Above I have provided the generic eligibility criteria to pursue BCA, so kindly tell from where and when you want to get admission in BCA course so that I can guide you for the particular one only.

Good Luck!!!