Salam alaikum , 7 brothers and 3 sisters from single father and mother. 2 sons died when the father was living and after few years both parents died. Now the remaining 5 brothers and three sisters who are alive are saying that in shariyate jafari if the son dies while father is alive his children’s do not inherit a single pie from their grandfathers property. Is that true in regards to yateem kids that they are told they don’t inherit anything from their grand father because their father died?