Reg: Apartment that i bought on laon

Dear Sir/Madam, I have typical headache with my property being occupied by my inlaws. Into the details. I have bought an apartment in bangalore in 2006 on loan. In 2010 i got married and in 2014 I went to Ireland. I took my family (Wife and 2 children) after the first six months once i got settled. As I am in Ireland my in laws took advantage of my apartment and started staying there. I was resisting right from day one but they have convinced my wife saying that until someone good or known people will come for rent they would stay. My Wife was deceiving me saying that it was given to rent and for 3 months they deposited the amount in my bank to make me believe. After that they told me that the rented family has left and no one is coming. When I spoke to the apartment management I came to know that my in laws never rented my apartment and they are staying there and also came to know that they told the apartment management that i would send the maintenance bills rather than them paying it. My father has expired and my mother stays in Delhi. When my mother spoke to my In laws about giving it to rent t..they started saying that it's their daughters house they have right to stay and never allow any one to come to rent. if someone tries(my family) to make them vacate they would put a dowry case on us . My wife started threatening me to do suicide if i take any action on her parents.. I am really in a situation where my wife supports her parents instead of me.If I want to talk to them they will never ever pick my phone..in case if I do it from other number the moment they hear my voice they will just hangup the phone.If I send any of my Friends to check they started threatening them. I am in a spot where I cannot come to India and do something about it. The apartment I bought with my own earnings and paying the loan every month is taken away by my in laws. Can you please advise me how to legally proceed on them.