You can file complaint before superintendent of police
If you want legal advise then you can call me on mobile no 9359867870
Advocate IRFAN SHAIKH
I am sorry to hear what has happened with your father. If the police aren't receiving your complaint and not registering FIR then you can send your complaint in post to both the Station House Officer of that police station and the commissioner of police as well and within three four days if you don't receive the acknowledgement of registration of FIR, then you can go ahead and attach the proof of sending complaint by RPAD and register a private complaint with the magistrate and then procced with the case of abetment to suicide.
For further queries, you can contact me on 7601090381 or firstname.lastname@example.org
What happened is very unfortunate, yes fir can be registered against the branch manager and ors for abetment to subside .
Police is bound to register FIR if refusing let the court give direction to register the FIR