I had horrible experiences with ATM's in Brazil. And you get screwed in my opinion with TC's. My first trip to Rio in many years and hit the ATM machine and after trying with no succcess with four different machines found out that these were for Brazilian cards only. But in the meantime since Brazil has such a high fraud rate my card was flagged by my bank due to the four fruitless attempts so
I had to call my bank the next day to get the hold off. There are supposed to be international ATM's at GIG, but not sure where. I charged the taxi to Ipanema on my credit card and eventually was able to get cash on my debit card at a local CitiBank branch. I had few hundred dollars and Argentine pesos as well which I would advise bringing a few hundred in cash with you just in case. Be sure and advise your local bank and credit card isssuers that you are going to Brazil. The credit card I charged the hotel on was blocked after that charge was made since I had not told them I was going to Brazil. Yet another phone call to clear that up once I returned to Buenos Aires. These were all US accounts by the way.

Sam