No. Rockstar has announced GTA 6 for PlayStation 5 (including PS5 Pro) and Xbox Series X|S only. There is no Nintendo Switch 2 version confirmed, and nothing suggests one is coming at launch.
The Switch 2 is a weaker console than the current-gen systems GTA 6 targets. Its hardware, especially in handheld mode, struggles with heavy open-world games. Rockstar has not even listed the platform in its official store pages, so any talk of a Switch 2 port is speculation.
Historically, GTA games skip Nintendo consoles entirely. Grand Theft Auto V never reached the Switch, and Rockstar has shown no interest in porting its modern releases there. The pattern is consistent.
For GTA 6 at launch, your only choices are the PS5, PS5 Pro, or Xbox Series X|S. A PC version is also unannounced, so those are your only options for now. Any Switch 2 version, if it ever materializes, would likely come years later, and even that is a guess.