There are no official GTA 6 PC requirements yet, so treat every spec list you see as a guess. That does not leave you stuck. Here is what you can act on now and what to ignore until Rockstar confirms it.
Use the check as a planning tool, not an FPS promise. Says yes? Keep your setup and do not spend. Says maybe or no? Fix the one weak part it names, and ignore any list claiming to be the official GTA 6 requirements.
Do not buy on a guess. Check your exact setup in 60 seconds and see the one part that matters.
official:Rockstar Games GTA VI page. Rockstar lists GTA VI for PlayStation 5 and Xbox Series X|S. FrameReady does not treat PC requirements as official until a PC source exists.