What is the ruling on land that was not distributed among heirs until one of them died, and he has children?

If the mother's heirs are limited to two sons, and one of them dies after the mother, then her estate is divided equally between them. The share of the deceased brother is then distributed among his heirs. Inheritance matters must be referred to the Sharia courts for investigation, as there may be wills, debts, or other rights that take precedence over the heirs' rights.