Share of illegitimate children to legitimate grandparents estate

Hi,

My father passed away and was claiming his share to his parents; estate. These properties were never transferred to his name. He has 2 siblings. My mother is alive and his 3 legitimate children (including me) and 4 illegitimate. My question is whether his illegitimate children still has a share to my grandparents' estate. How will their estate be divided if my grandmother has a will stating that my father's share be split among my siblings and I (legitimate only). What if there is no will? How will my grandparent's estate be divided among their children given my father has passed? Thank you in advance for any legal advice.

if your father died before his parents, then the illegit children have no right to inherit from your grandparents

if he died after they did, then they can inherit from his estate