Your logo should somehow capture the spirit of the sporting event and also reflect something about Rio and Brazil in general. How you do this will be up to you.
Your logo submission must include the olympic rings. The general format for this has been at the bottom of the logo for each of the past Olympic Games.
The designs should work well in colour or black and white.
Apart from that, feel free to submit designs that you feel match the challenge and tell the story of the event. Happy designing! :)