Marital Issue, Property Issue

Ramulu married another woman (Ramana) 30 years ago without giving divorce to Manga. Later when Manga filed a case, Ramulu agreed to give 1 acre of land (His father owned property) as maintenance & to settle the case mutually but did not made any written agreements. They do not remember the case details/number also. From 30 years Manga & their family are on that land and are farming it. Now Ramana says her father-in-law (Ramulu father) wrote on a stamp paper that he promises to give that 1 acre land to her at the time of marriage. Now he's not alive. Recently Ramulu got the Land passbook from the Govt of Telangana on his name. Ramana is fighting to get share for her 2 sons. Laxmi is only daughter of Manga. At the time of Laxmi marriage (2015) Ramulu promised to give this land as gift to her & Ramana was present on this event. In this land Laxmi sold 4 cents before 2015 without any consent of Ramulu. If we proceed legally do we get full right of property. Please advise.