After completing my diploma in mechanical can i go for some commerce related fields is it possible?
The best option for you to joinafter your diploma is to join bba or bcom. But I would suggest you to join bba as in bba the fundamentals of commerce are taught so that any stream student can go for it. But in bcom the fundamentals are not taught in details and are more easy for commerce students.
For a list of top colleges in India for bba are
Hope it helps