Event with simultaneous breakout sessions

I will be running an event with 250 participants, this will be split into 4 separate sessions as time slots

e.g 10:00-10:30 I will need room a) &room b) to run at the same time, 10:30 - 11:00 rooms a) &b) and for attendees to be able to choose which session they would like to attend.

How many attendees can i have in the main meeting and how many will be allowed per breakout room?

@breakoutroom @similtaneousevent @numbers