Ottawa is 2 hours behind Brasília
Best overlap: 10:00 AM to 6:00 PM in Brasília is 8:00 AM to 4:00 PM in Ottawa.
If you set up a recurring sync, 10:00 AM to 6:00 PM in Brasília (8:00 AM to 4:00 PM in Ottawa) is the natural home for it. Because you share 8 hours of the workday, there's no need to compromise; book the time that suits the meeting, not the map. Because Ottawa and Brasília don't both observe daylight saving, plan to re-check the overlap around March and November.