My Aunt (Father's Sister) didn't leave from my Father Property, What to do get her out from property

Sir, I am Rajgopal residing in Bhubaneswar area and our home located in the prime location in the town. A 12 years ago that property not valued much but now it's lot more worth. Coming to the problem part: My Aunt (Father's Sister) is a Primary School Teacher near by School and after permission of my father she reside with her one son, daughter and my grand mother (Father's mom) from 2001. In 2006 we asked her to take another home so that we can go to our home ( my mother is also teacher and her school 30 Km. from our home, so we stayed there from 1990-2010) but she refused to do that after lot of quarrel we decided to built our 1st floor building and move to our property and she always use her mother (Grandmother) to stay in our property and always blackmailing us to by telling that ("I sue you by using my grandmother that she was bitten by her own son (My father)"). She also file case against us to share from my father property but without enough evidence, court dismiss the case but problem now is she using my grand mother as weapon to us, so we can not get out of the property. Why my grand mother support her because she was married in 1989 with a high school teacher and after some days her husband got to know that she have relation with other married man, so he get her out from his home and her second husband worked in banks, he has 2 son and a daughter, he died just 2 years ago and the lady my aunt is very smart and he signed document before died so called 2nd husband of worth 1 crore property and she blackmail his family and after bargain she got her I guess 15 lakhs rupees from her 2nd husband property. so for this reason my grand mom always support her and she manipulate her always and my grandmother manipulate my father previously but my father is on right path. How we get my Aunt out of my father property and how to defend her threat (she use grandmother to case against my father, that he didn't treated her well, which is false. my father always silent because of his own mother, he is very innocent man), Please give some legal advice on that!