Both Series X and Series S run GTA 6, so support is not the question. Money versus image quality is. Get the Series X if you can afford it. The Series S is the honest budget pick, as long as you accept that the GTA 6 gap between them is not confirmed yet.
Own either Xbox? You are covered, keep it. Buying now: take the Series X if visual quality matters and the budget allows, or the Series S to spend less. Do not expect a confirmed GTA 6 difference between them yet.
Do not buy on a guess. Check your exact setup in 60 seconds and see the one part that matters.
official:Xbox GTA VI page. Xbox lists Grand Theft Auto VI for Xbox Series X|S with a November 19, 2026 release date.
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.