Do the children of a son who died before his father inherit from their grandfather who distributed apartments among his children during his lifetime, and do they inherit from their grandmother who died before their father?

The grandsons do not inherit from their grandfather if their uncle is alive, and their father does not inherit from his father because he died before him, but he inherits from his mother if she dies after him, and his share passes to his heirs. The grandfather's gift to his sons without his daughters is null and void if justice is not achieved, and the apartments must be returned to the inheritance. The deceased's estate is divided among his sons, with the male receiving twice the share of the female. The grandsons or brothers receive nothing if there is a son. Inheritance matters are complex, and one must refer to the Sharia courts for them.