Can I still play Gta5 online on Xbox 360?
Yes it is still possible. However, you do need an Xbox live account
I have an Xbox one s with Gta I'm very far there and so I can register my account there I'm already registered with the Xbox live acc from the Xbox one on the 360 but still have to buy a new gta5, that's normal
Sorry, I'm also overwhelmed. I suspect, however, that it does not work because the game on the Xbox one is newer than the one on the 360 and thus the compatibility is not possible. The game is probably too improved in the Xbox One version to run on the Xbox 360.
You can still play on the 360 GTA Online. However, you can no longer transfer a saved game from the 360 to the One, as this has been switched off. Transferring the GTA Story Mode or GTA Online user data from the Xbox One to the 360 was never possible anyway.
The only thing you can do is that you get expensive things in the game for free. To do this, you have to register your Rockstar account on a load console. Whether an Xbox 360 or PS3 does not matter, and it does not matter whether your account is already registered on the current gen (Xbox One, PS4) or still want to register it. So it goes from every Last Gen console (360, PS3) to Current Gen (Xb1, PS4) or PC.
This means you get things like the Duke O Death, an armored muscle car or the Dodo seaplane for online mode completely for free (and the infinite amount of times, so buy the Duke o Death 10 times for 0 $, for example)
This is the only feature you still get from the Last Gen consoles.