Rio de Janeiro is 2 hours ahead of Medellín
Best overlap: 8:00 AM to 4:00 PM in Medellín is 10:00 AM to 6:00 PM in Rio de Janeiro.
For a call that suits both sides, look at 8:00 AM to 4:00 PM in Medellín / 10:00 AM to 6:00 PM in Rio de Janeiro. Despite the 2-hour difference, an 8-hour overlap keeps things simple and gives both teams breathing room.