You can either Kick or Unkick users from a chat room. Kicked users will not be able to log in to the particular room until you Unkick them.

• Click on  a room you want to Kick or Unkick users from.
• There you will see users who are already in the room.
• Click on Kick button on user row to Kick or click on Unkick button to Unkick user.