Is a commerce without maths student eligible for BCA?

Yes, a majority of colleges will provide you admission without any problem but there are some top/popular universities which will not be able to get you admission into BCA. So, search for those universities which will provide you admission and suits your budget.

In most of the universities, maths is required for BCA. So, you are not eligible for doing BCA from colleges asking for maths as a subject in HSC. Rest, check with colleges not asking for maths as a compulsory subject.