A system for managing resources in a communication system including a plurality of systems, which do not have a permission for a first frequency band, includes a plurality of coexistence managers configured to, when a frequency band available for the plurality of systems is searched from the first frequency band, manage the plurality of systems for coexistence and frequency sharing of the plurality of systems in the available frequency band; a coexistence enabler configured to transmit and receive information of the plurality of systems and information of the coexistence manager; and a coexistence discovery and information server configured to support control of the coexistence manager over the plurality of systems, wherein predetermined messages are transmitted and received among the coexistence discovery and information server, the plurality of coexistence managers and the coexistence enabler to discover neighbor systems among the plurality of systems.