Moscow is 6 hours ahead of Brasília
Best overlap: 8:00 AM to 12:00 PM in Brasília is 2:00 PM to 6:00 PM in Moscow.
Keep meetings inside 8:00 AM to 12:00 PM in Brasília — that maps to 2:00 PM to 6:00 PM in Moscow. Around 4 hours of overlap is enough to work comfortably, as long as meetings don't drift to the end of one team's day.