According to a source within Rockstar Studios, claims TechRadar, Grand Theft Auto 6 is now currently under development, though Rockstar hasn’t revealed any sort of location yet.
TechRadar’s source also revealed that Grand Theft Auto 6 nearly went abroad, however nothing has come of these things ever since Rockstar reserved trademarks for “GTA: Tokyo” and “GTA: Bogota” in 2003. These, however, didn’t go anywhere, and GTA has remained in its cracked-out version of the United States for every game since its first.
Apparently, despite Rockstar seriously considering the possibility of an overseas Grand Theft Auto game, it was deemed “too challenging” to move the series outside the United States. One could also argue that Colombia and Japan don’t have the same kind of pop culture madness that Rockstar can make a thinly-veiled pastiche out of in order to give the series much of its jokes.
Something that also might have been a factor in the decision is that in order to move GTA to Japan or Colombia Rockstar would have had to change the various brands and cars that the series gameplay revolves around.
So yeah, it was probably best that Rockstar leave a Japan version of Grand Theft Auto to Sega and their Yakuza series.
GTA V rapidly became one of the best-selling games on the market when it released in 2013, generating 800 million dollars in revenue and selling millions of copies. As of May 2014, a year later, the game had generated nearly two billion dollars in sales.
There was a five-year gap between Grand Theft Auto 4, and Grand Theft Auto 5. If GTA 6 follows the gap between Grand Theft Auto 4 and 5, we may be looking at another released game in 2018 or 2019, but that depends on whether or not Rockstar wants to put in the same amount of effort that they did in GTA V.