Check your airline codes...I don't think you'd be flying Merpati Nusantara Airlines or Air Madagascar (Those are what pop up when I mouse over the codes) Maybe then you'll get the help you're looking for.
You need to be a bit more clear. I assume you are referring to UA? (IAD-GRU) UA has two versions of 763. One is for domestic use, the other for international use. See UA's website for more information on configuration.
Go to United.com and follow links Travel support > In-flight services > Seat maps > B767-300 Worldwide