tvOS 11.3 Jailbreak for Apple TV 4 & 4K
Jailbreak Apple TV 4K and 4th Generation Tutorial with Electra tvOS 11.3 Jailbreak
For those of you that still have their Apple TVs on tvOS 11.3 depending on your situation you can jailbreak it with one of the tutorials below.
Please note you may require a USB-C Cable
This video will guide you on how to complete the tvOS 11.3 jailbreak via Electra and Cydia Impactor the process is quite simple however it requires the correct version (tvOS 11.2-11.3).
Source: Best Tech Info