hi,

see most of the bca course in colleges eligibility criteria is candidates must pass 10 + 2 (Higher Secondary) with Mathematics as a subjects  (or) Computer Science with Mathematics.qualifying marks may differ college to college.

according to srm university, eligibility criteria for bca course is 10 + 2 (Higher Secondary) with Mathematics mandatory (or) Computer Science with Mathematics. (Minimum aggregate of 50%). Since you do not have mathematics in 12th course you can not get admission in any tier 1 college and it would be problematic for you even for your higher study. students can give nios exams from any 1 subject, so I suggest you to enroll in nios for mathematics in 12th course, then after passing mathematics 12th course from nios you may apply for many colleges which offers bca course.