Servers with the game "Command and Conquer: Renegade" except the port for connection, use "GameSpy (Query) port".
Therefore, to add a server, you need to enter not only the IP and the port, but also the "GameSpy (Query) port" of the server.
"GameSpy (Query) port" can be found by contacting the owners of the servers that you want to add to the monitoring. If you are the owner of such a server, then the information should be searched in the configuration of your server.
Standard Query-port: 25300, it is used on most servers.