Is it permissible, in Sharia, for us to inherit our grandmother's land, given that our father died before her, and we also have an inheritance from our grandfather's side?

A father does not inherit from his mother if he dies before her, due to the non-fulfillment of the condition that the heir be alive after the death of the one from whom he inherits. As for grandchildren, a condition for their inheritance from the grandmother is that there be no heir closer to her than them, such as paternal uncles. If there are male paternal uncles, they block the grandchildren from inheritance, based on the Prophet, peace and blessings be upon him, who said: "Give the prescribed shares to those who are entitled to them, and whatever remains is for the closest male relative." However, if there are no paternal uncles to block them, then the grandchildren are considered among the heirs. The distribution of inheritances must be referred to Sharia courts or specialized authorities to ensure correct distribution after paying debts and fulfilling bequests, identifying the heirs, and verifying the conditions and impediments to inheritance.