Right on grand parents property

Hi this is rajeev My grand mother has 9 acers property(got from their parents) and my grand father has 6 acers property(got from their parents) and house(site from their parents and house build by thier own).they have one daugther and one son. when I was 13 years old my father was expired and I am the son of son.my grand mother gave all her property to her daughter that means my aunt.later they sold that property.at that unable to question them because I am only 13 years old.now my grand father is ready to gave his property to my aunt(their daughter). In this 2 acers is in the name of my dad,(their son) when I asked my grand mother about this she told me that you don't have right to ask my property(mother property will goes to only daughter) you will half share from your grand father property only. Any one please help me in this context how I have to approach. For how much property I have right.