Hi Raman 

BCom is a three year full time under graduation course divided into six semesters. It offers knowledge in the subjects like Finance, Economics,  law, taxation and Management. And it is a degree course and is to be done by college itself.

Whereas, CMA is globally known course for the management in accounts. You have to clear paper to work with the Multinational companies. And  eligiblity criteria for the same is you should have graduated atleast. So ypu need a graduation degree before that as it is must.

So, you have to complete your graduation first and then you can go for CMa Course.