My Car hit by other vehicle from behind but am asked to pay

These are all threats for extortion.  If you have insurance, inform in police station the policy no, and once the other vehicle owner books a complaint, and provides such receipts with estimation, make a cliam from insurance company.  It is the driver behind that has to maintain safe distance.

Yes, this is a mere threat. If he wants to file the FIR, let him.

You say you have slowed down near a divider. I presume you  were going fast and stopped near a divider to ask for directions. With whom? How can you ask someone for directions when you are going alongwith the divider ie. extreme right of road? OK whether there was a free right turn near that divider and you have given right indicator? While slowing, did you give indication that you are slowing down ie. lighting up both rear lights?

Much depends upon eye witnesses in the matter. I hope there is a recorder in the car also which cannot be tampered where the signals given etc are getting recorded so that mistake of a driver can be pin pointed to some extent.

Same is the case even if you are driving to the extreme left of the road near the divider. It all depends, what signal/s you had given and whether you can prove that such signal was given.

If there is a CCTV camera installed by Traffic Police or Corporation, immediately seek such footage under RTI.