The Gran Turismo 6 servers will shut down in March 2018 and Sony Interactive Entertainment confirmed the following news with a brief announcemen.
Players will be of course still able to play offline after that date, but on March 28 they will be not able to access the game’s online services, including lobbies, community features, seasonal events etc.
Sony has published the following notes regarding the end of the Gran Turismo 6 servers for PlayStation 3.
Warning Regarding In-Game Credits
If you have deleted your game data after purchasing credits from the GT Store, please make sure to install/redeem the credits again before the end of the online service to have them available in-game. The installation/redemption of credits can be done in-game from [My Home] -> [GT Store] -> [Purchased Content]. It will no longer be possible to install/redeem credits after the end of the online service.
How to re-download Credits when your game data has been deleted
Even if you accidentally delete your game data after the end of the online service, it will still be possible to re-download and re-install the credits. To re-download them, go to the [Download List] in the PlayStation Store, or go to [PSN] -> [Account Management] -> [Purchase History] -> [Download List] from the PlayStation 3 XMB (Cross Media Bar).
Regarding the “Track Path Editor”
With the end of the online services, the distribution of the “GT6 Track Path Editor”, currently available on “Google Play” and the “App Store”, will also end as of 28 March 2018. After the end of the online services, it will no longer be possible to transfer track data created with the “GT6 Track Path Editor” to Gran Turismo 6.