What is the most stable version of Unity TECH stream or LTS stream?

Curious what is the most stable version most suitable for publishing?

 

You can read the Unity official docs on what each stream is intended for, but if you select based purely on that and have a problem, well, it's a problem.

What will actually matter is how your game, which uses the features you want to use, runs on the specific targets that you are intending on releasing to.

Unfortunately there is only one person who can accurately assess this. Keep in mind that if your target is one that receives regular OS updates (most targets do), then your assessment may also change over time without you even changing anything.