Grand Theft Auto 6 is definitely on the table but at this point, there is no reason why we should be getting excited about it right now because we might have to wait for years before we see something from GTA 6.
Rockstar has suggested that they might be working on the GTA 6 already but if they are, it is probably just the start of the development process and nothing has really been confirmed yet. The next game that we will be seeing from Rockstar should be the next Red Dead Redemption 2 game which will only be arriving in 2018.
That means the GTA 6 will only be arriving in 2019 or possibly even later. With GTA 6 being so far away, what can the GTA fans look forward to? Well, Rockstar has been releasing DLC after DLC for the multiplayer mode so they have that.
Fans are also hoping that Rockstar might still work on a single-player DLC soon although we dare not hope for too much at this point as it does not look like Rockstar is interested in doing that.