Harassment

Is there any document that the house is in your name?  Or you are thinking that as you invested some money and hence it is in your possession? If the house is in your name, then he cannot get anything in the house.

House is the name of my father who passed away 10 years back.. 

SInce the house is in the name of father the legal heirs has right to share. What you can do is to file a suit for possesion and declaration . You have to prove that the house was in your possesion and that the property is built by your personal expensises. YOur mother is alive she can testify in your favour

File declaration , injunction and possession suit against him  your mother as witness and your loan transactions may help you .

In such situation do not expect your mother (who gave keys to him) to depose in your favour.

I took possession of my house. Can I let out or need to get injunction order?