I have two brother and one sister with my family. last three years back, My father gave me two part of land gift deed. which has properly registered and all members singned in sub register office. I given unregisterd documnet for 15 lak to my sister for three years, now it is expired. She asking me to register a part of land on her name for an register agreement, but now one part of land docuemnt under loan mortgate.. in that case my father or my family member can cancel my gift deed with out my knowledge ?