Gpa registered

Hi We are 3 brothers and 1 sister all are married I am the youngest one; my Father left Feb 2016 due to cancer , found in 2011 Where for entire treatment of my Father I have done the expenses borrowed money from the market at 10% & 7% still unpaid where none of my siblings are ready to bear the expenses after all those part my Father transferred property in my Name via GPA Registered in 2014; after which my brother made another GPA Notarized in my absence; they have stolen papers from my father who holded the papers since the time he made GPA Registered in my name. Now they are disturbing us daily threatening and not ready to pay single penny at all; 3 floors are build ground floor has 2 bhk, First floor has 2 RK Set, Second Floor has 2RK Set. what action I can take, I want possession and my papers back. They also tried to take electricity connection in my absence and without my knowledge. while GPA registered was transferred in my name from my father to me no money transaction was done...Register under Book IV Volume 1865 pages 174-179. In Delhi I am expecting best review or suggestion or guidance by all best lawyers