Succession of the Property

My Aunt Name "Mangamma" : Recently Died (61) on 29th July 2014. Got married in the year 1969 - She was a minor then. Got separated within a week from marriage, from her husband (But not divorced legally). Husband got married to an another woman in the same year and he has 2 Sons now over 30 years. At the time of marriage, her (Mangamma) Grand Father gifted and registered an Agricultural Land of 1 Acre in both Husband and Wife. (in the year 1969) But all these years, the property is enjoyed by Mangamma and their relatives. And got Pass Books for the land from the Govt of AP in the name of Raghavamma (Mangamma's Mother) Recently (in the year 2012) Raghavamma (Mangamma's Mother) registered (under gift settlement) the same land of 1 Acre in the name of Rama Thulasi (Mangamma's Sister's Daughter), who is raised my Mangamma after the death of Rama Thulasi's mother, for last 20 years. Now the EC is showing only this transaction. ESeva, govt website of AP Govt, is also showing the same transaction. Now the Husband of Mangamma is claiming that it is his property. Kindlywhose registration is valid now. Do we have to surrender the land to him..??