How much you can get
For delays and cancellations Brazil’s rules give assistance rather than a fixed amount: communication from 1 hour of delay, food from 2 hours and accommodation from 4 hours, plus a refund or rebooking. Passengers often win damages in court.
Denied boarding is different: the airline must pay on the spot 250 SDR on a domestic flight and 500 SDR on an international one (SDR is the IMF’s unit, about €1.2), in reais.
Source: www.gov.br. This is a summary, not legal advice.
How to claim it yourself
Contact the airline, then use consumidor.gov.br; damages beyond assistance are claimed in court.
The claim services we work with (AirHelp, Compensair) take EU and UK cases. Under these rules you claim from the airline directly, which is free.