To Jailbreak Apple TV 4, you'll need to download Pangu9_ATV_v1.0.zip, a USB-C cable, a Mac, Xcode, and an eligible Apple TV 4. Although, the team behind this jailbreak has stated to in order to successfully jailbreak your Fourth-Gen Apple TV you must have a paid Apple Developer membership.
Reminder: The Pangu9 jailbreak tool for the Apple TV 4 only allows SSH access for now and doesn't feature a GUI interface like Cydia.
Unfortunately, since there is no way to downgrade Apple TV 4, those who upgraded to the latest tvOS release will no be able to take advantage of this Jailbreak anytime soon.
Pangu