Is there a problem to drive non MH no vehicle in Pune?

Depends on where you are in Pune. I've been here for close to 2 years with my friend and he drives a non MH vehicle and hasn't been caught yet.

Indian Police will fine a normal person for an incorrect number plate And bail out a drunk minor who killed 2 innocent people using his dad's Porche which he earned by tax evasion.🇮🇳

There is a catch for this "6 months" timeframe. Just keep a toll receipt handy to show you travelled from outside

It is traffic rule across the country, you need to get local registration within 6 months of shifting there. There is exception for NCR where HR, DL, and UP numbers are allowed to ply

Yes you would be fined when caught.

Better to change it to MH or BH series (if applicable).

Or maybe get a new vehicle entirely with the MH or BH series (if applicable).