What should I study after completing MBA in finance and marketing?

In my opinion, you should not make up your mind before starting anything. You can see the subjects yourself and then decide. You should decide after experiencing it.

If you are good in accounts, then you can go for finance. If you feel that you are extrovert and have good communication skills with good convincing skills at the same time and you are comfortable travelling to different places, then you should opt for marketing.