This message indicates the port number on which the clients is listens for server requests. If the port number in the message differs from the default value or what you specified with the TCPCLIENTPORT option, it is because the port was in use by a different process.
Processing continues.
Normally no further action is required. If you require TSM to use a specific port number, you need to configure your system or applications so the number is avaible. Restart the TSM client and confirm it uses the desired port.