Hello Selbin. I wanted to tell you that as such there is no exceptions available in CA course if you are also doing M.com.  The M.com is just an additional qualification. For pursuing Mcom you have to take the permission from the Institute of Chartered Accountants of India. I want to add some points which you will find helpful. The advantages of doing Mcom along with CA can be :- 

1. Writing the exams of Mcom will give you a practice of writing exams till you appear for the CA final exams.

2. You will get some additional knowledge which can help you in CA course.

3. If you are planning for further studies in abroad it is necessary to have  16 years of education. 

4. If you want to do the practice in CA it will help to cover some specific area of Audit .