Injunction on sale of self acquired property gifted to me by my father

Hello, my 80 years old father gifted me his self acquired property (registered properly at the sub-registrars office with taxes and stamp duty duly paid) which he bought from his own income, free of any conditions on 2016. He has 3 more daughters who were torturing him mentally for property share. So he decided to gift it to me cause he trusts me with his property. The transfer has happened with my mother's full support and knowledge. But without my sisters' knowledge. Can my sisters get injunction to stop me from selling the said property ? If they do how do I find it out ? I recently came to know from my mother, that, last year in my absence (I live in a different city) my 3 sisters have made my father and mother sign some legal documents forcefully. I guess about seeking injunction from the court so I can't sell the property. Is this possible? If yes then how do I find out if they have filled for injunction or not. If not then what other papers can they make him sign to harm me. Also they threatened my father and made him say that the transfer was made fraudulently and recorded it. Although on recent questioning he still admits to me and my mother that he has done it without any pressure and he knows what he did. What do I do now ? Thank you.