Eviction from property ; False FIR.

I have an office which my father gave on rent to a person to run an agricultural magazine. He has been using it from past 11 years but has not been paying rent from past few years. My father also had a notary agreement with that person to sell the office which had an expiry period of 6 months which has expired, and in which he was unable to pay the total amount decided. Now when I told him to take the money back that I had received and to vacate the land he filed a false FIR against me and my father. I would be highly grateful if you would please tell me how can I get the possession of my office.