Whether the gift is valid or not??

Dear friends ,

                    Mrs.X ownd a house. She gifted the house to her relatives by preparing the gift deed and paid the stamp duty on the same.At the time of transfering the property by the revenue authority claimed that this gift deed is void-ab -intio and the the tranfer of the property as gift can not be considered.

                   Wheteher the Claaimed made by the revenue authority is corrrect??

                    Is there any judgement relating to above case is found then kindly requested to refer the same.

                   I also want to know that is there any law relating to the Gift is prevailing ,if yes then kindly requested to give the name of the same.