Do the paternal uncles and aunts of the questioner have a share in the apartment owned by the heirs, approximately 20 years after the grandparents' death, knowing that the apartment was rented in the father's name at the time of his death?

The death of a tenant does not invalidate a lease contract, according to the majority of scholars. The leased usufruct transfers to his heirs. Accordingly, the questioner's paternal uncles and aunts have a right to their parents' share of their son's inheritance. If the apartment was owned by its owner through deferred installments, then each heir has a share of the inheritance and is responsible for their portion of the deferred installment payment commensurate with their share.