Is the oral distribution of land carried out by the grandfather and father valid, and do the grandchildren have the right to claim their share after the death of the father and grandfather and the uncles' denial?

Issues of dispute and contention are to be resolved by the Sharia judiciary or arbitration, not by a fatwa. If the grandfather's distribution of land was a transfer of ownership after his death, then it is a bequest to an heir, which is not enforceable without the permission of the remaining heirs, based on the Prophet's (PBUH) saying: "Indeed, Allah has given every rightful person his right, so there is no bequest to an heir." In this case, the father who died before his grandfather has no right to the land, as the bequest becomes void due to the death of the legatee before the testator.

However, if the distribution was a transfer of ownership during his lifetime (a gift), then justice must be observed between male and female children, based on the Prophet's (PBUH) saying: "Fear Allah and be just among your children." If the giver dies after the gift, it becomes enforceable, provided that the recipient took possession of the gift before the giver's death; otherwise, it becomes void. So, if the father took possession of his share of the land, then you have a right to it; otherwise, you do not.