Clans are a feature in Rush Team, where players can create a group and all of the members of the clan, will have the clan's name alongside their name. Clans currently have almost no features. Each clan has a master and may have an assistant. Master is the founder and can ban members, assign an assistant, invite members, select a new master and delete the clan. Assistant can also delete and invite members but can't assign any other assistants (because there can be only one assistant) and can't delete the clan. Also, the members of a clan their own clan chat in the lobby. Messages sent in clan chat will be only seen by other members of the same clan.
Being in a clan doesn't give you any real benefits.
By default, you can only have 10 players in your clan. You can purchase more slots for your clan from the Rush Team shop. 10 new slots will cost you 1000 ASR cash. There is no known limit to how many player slots can be in a clan. The biggest clan called "umnite" has exactly 220 members.
The most known clan in the game is most likely ''Game-Masters''. All of the members there are the game mods or developers.