You can access and edit your device list here.
Manufacturer: Type in your manufacturer brand
Category: pre-selected as 'Connected devices'
Model and info can be found when you open Settings (cogwheel Icon Home screen - top right) > About
Model (example: MIBOX3)
4. Model Release Date:
5. Operating System: Android
All Android TV devices run Android OS
6. OS version:
OS Version info can be found when you open Settings (cogwheel Icon Home screen - top right) > About
7. OS Release Date
Check this page for your Android OS version release date.
This is an example how the final device adding screen would look like: