For BCA there are no need to have Mathematics as a compulsory subject. SO even if you have no mathematics, you have nothing to worry about it.

Some of the low fees colleges (less than 1 lac total fee for three years) in West Bengal for the course of BCA:

Aliah University, Kolkata

Hijli College, Paschim Medinipur

The Calcutta Anglo Gujarati College, Kolkata

Midnapore College, Medinipur

Kharagpur College, Paschim Medinipur

AMEX, Burdwan

Mahishadal Raj College, Purba Medinipur

For more colleges you may visit the link below:

https://it.careers360.com/colleges/list-of-bca-mca-colleges-in-india?state=West%20Bengal&degree=B.C.A.&fee=Less%20than%20100000

To know more about Computer Application as a career visit the link below:

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

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