To create breakout rooms, you must be a meeting organizer or a presenter in the meeting organizer’s organization who’s been appointed a breakout rooms manager.
Before a meeting
If you create breakout rooms before a meeting starts, you can invite up to 300 people. As soon as the meeting starts, you can open the breakout rooms.
Select Calendar in Teams.
Double-click a meeting to expand its details.
Select Breakout rooms > Create rooms.
Choose the number of rooms you want (up to 50).
Select Add rooms.
Select Assign participants.
Choose how you want participants to be assigned.
Select Next > Save.
During a meeting
Select Rooms in the meeting controls.
Choose the number of rooms you want to create (up to 50).
Choose how you want participants to be assigned.
Select Create rooms.
Tip: To add another breakout room during the meeting, select Rooms > Add room in the meeting controls.