The "Grand Theft Auto" video game series is ridiculously popular. The last game in the series, "Grand Theft Auto V," moved more than 70 million units as of November 2016 - it originally launched in September 2013. Most entire game franchises never reach that kind of ridiculous number of units sold, let alone standalone games.
Given that, it's not exactly surprising to see that the company behind "Grand Theft Auto" is working on the next entry in the series. It's an expectation, even.
Our first confirmation of just such a project in development comes from the resume of Tim Neff, an actor-for-hire who appears to have done some motion capture work on the next "Grand Theft Auto" game. His resume even outright refers to the game as "Grand Theft Auto 6" - presumably the game will use the traditional Roman numerals it has in the past ("Grand Theft Auto VI").
Neff also lists motion capture work for another game produced by Rockstar Games: "Red Dead Redemption 2," an upcoming sequel that's officially announced as in-production. Of note: Rockstar Games hasn't officially announced a new "Grand Theft Auto" game, nor did the company respond to request for comment.
Neff is a professional actor who's appeared in a variety of television shows and films. His current video game motion capture work appears to be limited to the two Rockstar projects.
Other than the name "Grand Theft Auto 6" showing up on Neff's resume, the project has never been officially announced or given a name. As such, there's no information about it other than what we can safely guess based on past games. It's likely to be an open world-style game, for instance, and it's likely to be set in the modern era; it's also likely to be set in a major city, like New York or Los Angeles (albeit slightly fictionalized - Los Angeles became "San Andreas" in "Grand Theft Auto V," for instance).
Of course, it's entirely possible that the resume listing was fabricated; Neff and Rockstar didn't respond to request for comment.