It depends. Samsung discontinued Tizen updates for 2015 models. You will likely remain on version 6.08.x. Consider using an external streaming stick (Chromecast with Google TV or Fire Stick 4K) to get the latest features.
For tech enthusiasts, enabling "Stats for Nerds" (via 4 taps of the "More" button) now shows: Smart Tv Youtube 6.17 391 Download Latest Version
It often bypasses the forced update screen that plagues older, official YouTube app versions. How to Download and Install Smart YouTube TV (6.17.391) It depends
The safest way to get the latest build is through your Smart TV's native application marketplace. Samsung Smart TV (Tizen OS) Press the button on your remote. Select Apps from the bottom menu. Consider using an external streaming stick (Chromecast with
: Go to Settings > Apps > YouTube > Clear Cache to fix corrupted installation loops.
To function correctly on older hardware, it often requires the installation of the Crosswalk Project runtime alongside the APK. Downloading the Latest Version