Does the paternal uncle have the right to claim his share of the questioner's mother's apartment, given that the questioner's father passed away before his mother (the questioner's grandmother), and that the questioner's brother was the one who paid off the father's debts and bought him the apartment that the uncle is now claiming?

"Dispute resolution falls under the purview of the Sharia courts. If the apartment your mother lived in was owned by your father at the time of his death, it is an inheritance to be divided among his heirs, including your mother. Your mother's share does not cease upon her death; rather, it passes to her heirs, and her son is among them. A brother's financial assistance to his father in purchasing the apartment does not preclude the grandmother's right to inheritance, for money given by a son to his father becomes the father's property unless it was a loan. Scholars differ on whether a son can claim a debt from his father, and if the father dies, whether the son can take his debt from the estate."