Hi! So I downloaded Photoshop CS6 Extended and had registered, but I wanted to check if I have done it properly and if my PS is already registered.
The question is how do I check?
It is the extended version when I start PS, and I can see the 3D tab between View and Filter, but when I click on it, everything else is grey and I can't click it.
You can access your Adobe on this web site account in check all your registrations in My Products.
As for your issue, a lot more info is needed:
Please read this FAQ for advice on how to ask your questions correctly for quicker and better answers: