Hello! First you need to join or create a Group; If you create a group, go to the tab community and click on "My Clan", go to admin tools and enable your clan. You need at least 3 players to be in the group an these players need to set the group as their clan in the "Interact" button that's under the Clan Name, once all the players have enable it your Clan tag will be available in game. Hope it helps!