Wife harrashing me and my family by blackmailing about divorce

My wife and my mother in law continuously harassing me and my family by blackmailing us filling fake FIR in police against me and my mom.My mother in law last week came to us and talked in very bad language to my mom.My mom is high BP patient i dont understand what to do.My mother in law says law is in favour of them that no one can do anything.My whole family is in tension as never did anything.When i asked my wife what is her problem she told me shr dont want to live with my mom,she want to live separately. what should i do plz help...