What should be the maximum gap between B.Com and MBA?

2-4 years' work experience prior to pursuing MBA would be a great advantage for career growth.

You can do MBA whenever you want after graduating. But most of the candidates try doing MBA after 1-2 years of experience.

There no such gap mentioned in any rules and regulation. It is good if you have more than 2 years of work experience after B.Com and then do MBA. It will be an added advantage.