If you look up gta vi free download, the verified details show the game is a paid release

https://wiki-planet.win/index.php/GTA_VI_for_free:_czy_mo%C5%BCna_liczy%C4%87_na_darmowe_pobranie_GTA_VI%3F

If you look up gta vi free download, the verified details show the game is a paid release, while only promotional assets like wallpapers and trailers are available for free.