Major game launches are a common magnet for pre-order scams. GTA 6 won't be any different.
Common patterns
Sites offering pre-orders at suspicious discounts. Offers claiming the PC version is available now that don't come from Rockstar. 'GTA 6 mobile' download scams (no mobile game has been announced). Beta key offers.
How to avoid
Only pre-order through official platforms: Rockstar Games Launcher, Steam, or the respective console store. Anything else is high-risk.
Pay special attention to content featured in social media ads.