Any person, whether notified or not, may become a party to the proceeding for the purpose of filing objections to the granting of the relief prayed for in the petition or any part thereof either by filing in court an answer showing that he claims some interest in the premises and stating the grounds of his objection or by filing a cross-action praying that the title to the land or some interest therein be decreed to be in him and be registered accordingly.
Georgia Legal Code