See there are no such obligations regarding Mathematics for the eligibility of BCA. So you can admit in any of the colleges in Delhi for BCA if you have atleast 50% marks in 10+2.

Some of the best collegea for BCA in delhi:

• Ambedkar Institute of Technology, Delhi
• GGSIPU Delhi - Guru Gobind Singh Indraprastha University

For more colleges visit the link below:

https://it.careers360.com/colleges/list-of-bca-colleges-in-delhi

I hope my answer helps. All the very best for your future endeavors!