If nobody injured if I banged somebody car from back that Tata Nano from figo & all the major damages happend for my car more & nano only back bumper slight damage is there then I have to pay to nano owner. They are giving me fake bill of 10k for 3k bumper & threatening me that they will do police complained after 20 days of the incident. This there any law which I have to pay for that & any action I can take for that fake bill.
you certainly can contest such bogus claims. Be as that it may, it is for the insurance company to pay such damages as your car must be insured.
Ask your insurer to handle such third party claims , but for that An FIR is a must.
Proceed in accordance with law.