Is it good to go for SAP MM after MBA in finance?

An MM consultant does need working knowledge of FI and vice versa. In your case, you will have clarity in the finance area already when you start. Finance knowledge will help in gaining expertise as an MM consultant.

If you want to go to MM, then definitely YES. I have many of my colleagues started their SAP career right after MBA in MM and FI. Both sets are doing well in their careers.

SAP MM and FI are very closely integrated modules. An MM consultant does need working knowledge of FI and vice versa. In your case, you will have clarity in the finance area already when you start. Finance knowledge will help in gaining expertise as an MM consultant.