if the property is already partitioned it is under limitation act, but if there was no physical partition and both your and aunt occupied area without partition then a suit for possession in accordance with area mentioned in gift deed can be filed.
Also the gift deed should mention correct measurements of the property so if they got more area then specified you can file a suit for possession and eviction of your aunt from that area.
Also if there was no actual partition ever done by meats and bonds with respect to the deeds a partition suit with meats and bonds can be filed.