gift Settlement deed without the knowledge of the children

Hi, my grandfather has bought a land and he has 4 children(3son 1 daughter). my grandfather has passed away without dividing the property. in 2014 my father has given his rights of the land to my aunt without my and my sisters knowledge as settlement( my father also passed away in 2014). at the time of settlement I and my sister is a major. Now we are trying to get the land since we are also have the rights on the property . is this possible. Please clarify