This is a Criminal Offence. They have criminally intimidated and then have done physical assault / hurt too and threatening you to sell your property.
I am extremely surprised if you have not approached the police yet! What were you waiting for after the first incident of threatening received from them? IF they have physically harmed your relatives including your sister-in-law a strong case can be registered against the accused.
If the police is not registering the F.I.R then you can escalate your matter to higher police authorities and even after that if nothing happens, you can file a case U/s 156(3) of Cr.P.C. You can also file a criminal case.
Besides, I hope whatever you have stated must be backed with strong evidences/witnesses. If not, start collecting evidences & spread this matter in the neighborhood as you may need it later while taking legal action. You can also take the help of social media or local news channel to support you in this matter. If you do not accumulate strong proofs/evidences, your any effort to approach the police or Hon'ble Court will not be much effective.
You must contact your local Advocate, give him/her the full background & details of incidents to get an accurate advice from him.
Thanks & Regards
Advocate Abhishek Sinha
+91-70459 49997
