Can I get admission for BCA if I have studied computer subject instead of maths in 12th (commerce)?

Yes, you are eligible, not only commerce students instead if you are from any stream then also you are eligible for admission to BCA, even if you're from a non-mathematical background. Although not every university will be able to provide you admission, so the most important thing you have to do is

Yes dear , you are eligible for taking admission in BCA programme in Lovely Professional University even your 12th class stream was commerce . The eligibility of course is - Pass with 50% aggregate marks in 10+2 (with English) or equivalent. 

Thank you .