Is GTA 6 a sequel to GTA 5?
GTA 6 is the next mainline Grand Theft Auto game, but it's a fresh story with new protagonists (Jason and Lucia) and a new setting (Leonida). Rockstar has not connected it directly to GTA 5's story.
New characters, new map — not a direct continuation of GTA 5.
The GTA 5 cast has not been confirmed to appear.