Can I do MBA after a short Diploma?

You need to be a graduate from any stream to apply for MBA.

I think MBA requires a minimum educational qualification graduation in any stream. In addition to that you need to appear in management entrance test like GMAT, MAT, CAT. Every college & B-school has its own cut off criteria which must be fulfilled in order to get admission. You have not mentioned

You need to be a graduate Sonam to apply for MBA.

No ,graduation with 50% minimum along with Entrance exam if you want good ,college