Originally Posted by RafKa

There are no domestic lounges at GIG, and no arrivals lounge. Your options are limited to a (grim, windowless) day room at the hotel in T1; a room at the Lynx hotel, or, as others have suggested, take advantage of the light traffic and check out the city (check your bags through, or put them in left luggage).

Finding a "local friend" with a car, you could have a lovely tour of Rio's main spots, and perhaps lunch at Fogo de Chao, or whatever. Beats 12hrs at GIG!
https://www.rentalocalfriend.com/en