Yes,you can do the same MBA after your completing B.com .
because this eligibility is graduation. every candidate who is graduate in any stream are apply for this course.
this is post graduation course.
this have many examination for the MBA. some are;
some state level entrance exam.
& some other or sepetate university exam which is counducted by any universtiy.
but CAT is conducte by the whole national level entrance exam which is conducted by the IIMs.
any one IIM conducte this exam.
Mat has II class national exam. which is going on the B level schools .
some good instutes for MBA.
1. Aligarh Muslim University
2. Delhi University
3. Indraprasth University
4. Banaras Hindu University
for more information visit the website for exam dates or course
best of luck..................