See mathematics is not a problem for BCA. But in general for the BCA course we need at least 50% marks in 10+2. Now as you have >50% marks then you will not be eligible for the BCA. You will be eligible for the course if you are from SC/ST i.e., Reserved category as 5% relaxation is provided to the group.

To know more about BCA visit the link below:

https://www.careers360.com/courses/bca-bachelor-of-computer-applications

Some of the colleges for BCA in kolkata:

Aliah University, Kolkata

Techno India University, Kolkata

Techno Main, Salt Lake

IEM Kolkata - Institute of Engineering and Management

Amity University, Kolkata

For more colleges you may visit the link below:

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

The course fee ranges from 50k to 2lac according to your college.

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