If I were you it's A Big No...
Yes one can do that by putting double load on your head but you'll end up gradually because while pursuing B.com, you'll have to choose the subjects/ courses in all three years from thre different types of courses that includes: Foundation courses, Elective courses, and Application oriented courses.
Along with these subjects, you'll need to study awareness course on Environment. So, inorder to obtain B.com you have to secure 96% marks over a min period of three years and max period of six years.
For clarification, take a look of the courses during your 1st year which are: FEG-02, FST-1, FEG-1, & MSW-009.
The 2nd year courses includes accountantcy and theories courses: ECO-1 TO ECO-14.
The 3rd year courses are: AFW-(E), AWR-(E), AWR-(H), CTE-03, CTE-04, CTE-05, AOM-01, ASP-1, AHE-1, AMT-01, AMK-1, AED-1, ART-1, ACC-1, ANC-1 & ACS-1.
My suggestion is you initial step is to complete B.com at the first place before opt-in for MCA.
Hackers never learns but always wins!