Here is a list of commands you can use in Tribes:

/t claim – claims the chunk you’re standing on for your tribe
/t create <name> – creates a new tribe
/t invite <player> – invites a player to join your tribe
/t help – shows this command list
/t join <tribe> – joins an existing tribe
/t kick <player> – kicks a player from your tribe
/t leave – causes you to leave a tribe
/t list – lists all tribes
/t map – shows you a map of your surrounding area. Plus signs (+) are claimed territories, equal signs (=) are unclaimed territories that are nearby claimed territories, and hyphens (-) are unclaimed wilderness.
/t pvp <on|off> – enables or disables PvP for your tribe
/t show [tribe] – shows you information about a tribe
/t territory – shows you territorial information about the chunk you are standing on
/t uninvite <player> – retracts an invitation that was sent to a player
/t unclaim – unclaims the territory that you are standing on for your tribe

Type /t <command> help to see help for a specific command