Legal right to claim share in great grandfather's property

Dear Sir, My great grandfather had a self acquired land by way of gift from his master and he gifted a part of it to his daughter during her marriage, after his death in 1977 he was survived by 2 sons(one being my grandfather) and 1 daughter. Later his daughter died in 1988 and his elder son(my grandfather) died on 2006. Although no partition deed were executed between my grandfather and granduncle municipal taxes are in their respective names. My grandfather had 4 sons my father being the eldest one died in 2016 he is survived by a son, a widow(my mother) and a married daughter(myself having 2 minor child). Now the problem arises is that my mother, my brother and her 3 brother in laws(my uncles) are executing a relinquishment deed in favour of my great uncle against money without giving be any notice regarding the same. Kindly suggest what are my rights and what shall I do now to save my interest in the said property.