Mother gifted property to son

Hello sir, A mother gifted property to her son by gift deed in the year 2002. This person has sold this property to a A person in 2015.with registered sale deed. This A person has sold the same property to B person with registered sale deed in 2017. Now the son has saying my mother has not gifted the property to me. but by fraud i got the gift deed. In 2016 the same mother she has given gifted the same property to her daughter in 2016, Then the A purchaser has gone to court filed a case , after a period court has order to cancel the daughter gift deed by decree in November 2016, through the decree, registration department has also cancelled the gift deed and put a comment on the information in registration department that this gift deed has been cancelled by the court But the hot copy with the daughter with the help of this cancelled gift deed document she and her same brother planned to occupy the same house and went to court and make a false case that : sister is a owner/ brother is a tenant. sister has asking a court to vacate her brother from his house after a while both sister and brother given a memo to court that send us to lok adalat for settlement lok adalat has given award. again she went to court and open a E P and after a while court has order a delivery of possesion then the baealif has come along with police and vacated the B purchaser from the house.