Alfonso
I am not sure what you are trying to do or why you are trying to do it. Why would you want to, or need to, change the TACACS port?
But you asked how to do it and there is an answer to that. I am running 12.3(11)T on some routers. In that version there is a config option to change the TACACS port. tacacs host
portHTH
Rick
HTH
Rick