As well as confirming that it's in development, they say that its codename is Project Americas as the game will take place over multiple countries: namely, Brazil in a fictional city based on Rio de Janeiro and Vice City in the US.

What city is GTA 6 based on?

Liberty City is a stand-in for New York, Vice City is Rockstar's version of Miami and San Andreas is all of California with Los Santos being LA. Now, it seems like Chicago is going to be added to the mix. According to insider Matheusbr9895, he's “80% confident” that GTA 6 will see some new locations.

Where is GTA 6 set to be?

An alleged leaker by the name Onion00048 has suggested that GTA VI will take place in Vice City, but also feature Liberty City and parts of South America. We'd previously heard rumours of multiple cities and a Narcos-inspired drug smuggling story for the game, so this isn't too out of the blue.