Consoles settle half of this question by themselves. PS5 and Xbox Series X|S do not run modified game code, and GTA 6 launches on those two platforms only. Whatever Rockstar’s position on mods turns out to be, it will not be relevant on launch day.
The PC half
Every GTA modding scene worth mentioning has lived on PC, and there is no announced PC version of GTA 6 - no window, no platform listing, nothing. So the realistic sequence is: consoles first, a PC release at some unannounced later point, then whatever modding follows it. Each step after the first is assumption.
Rockstar’s complicated history here
The studio has never officially supported mods, but its enforcement has swung between tolerance and takedowns. Single-player mods were largely left alone for years. Tools touching GTA Online were pursued hard, most visibly with OpenIV in 2017, which Rockstar walked back after a backlash.
Then in 2023 Rockstar bought Cfx.re, the team behind FiveM and RedM - the roleplay frameworks the community had built on GTA V. Bringing that inside the company was a genuine shift in posture. It has not, however, produced a single statement about GTA 6.
What has not been announced
- Any mod support, official tools or SDK
- Any server framework for GTA 6
- Any PC release date or window
- Any policy on single-player modification
The reasonable expectation
Given the Cfx.re acquisition and the money in roleplay, some sanctioned form of community server tooling eventually seems more likely than not. “Eventually” is carrying the weight in that sentence. Our RP and online page follows the topic, and anything official goes into news immediately.