Dear Querist my opinion on your queries are as under:-
1. When Sessions court has set aside MM order, what the other party is trying to persue now in MM court?What options it must be trying?
Opinion:- when the session court set aside the order of MM it means the court re hearing or court passed the order to registered FIR?
2.What is role of MM court now?
Opinion:- its depend on the order of the session court.
3.What are the possible outcomes?
Opinion:- FIR will be registered.
4.Any action which is advised to be taken by us?
Opinion:- who are you? If accused then after FIR apply for anticipatory bail and fight the case on merit.
5. Any cause to worry about?
Opinion:- call for consultation.