No PC version of GTA 6 has been announced
GTA 6 launches on PS5 and Xbox Series X|S only. Rockstar hasn't said anything about PC.
Rockstar has only announced GTA 6 for PS5 and Xbox Series X|S. Take-Two's boss said in May that the game has been announced for console only so far.
One report in October claimed a PC release in early 2027, based on anonymous sources. Rockstar hasn't confirmed it, so treat it as a rumour. GTA 5 reached PC about 18 months after it first came out on consoles.