Can I skip one subject as an additional subject if I failed in 2 subjects?

You have to clear at least 5 papers in order to be eligible to apply for higher education anywhere in India with English as one of the compulsory subjects. Unless you clear 5 papers minimum, you are not an intermediate or 10+2 hence not eligible for admission anywhere.

I would like to tell you that you need to pass your all subjects in 12th as you are a CBSE student and after that only you can get admission in B.Com.