[Kruzin]

The description you have is all you need...transmission/t-case harness.

Unfortunately, you aren't going to find a new replacement harness. That Jeep is over 20 years old, they don't make those harnesses any more.
Car manufacturers generally stop making/selling those kind of harnesses a few years after a body style goes out of production. And there isn't nearly enough of a demand for an aftermarket supplier to make these very specific type of harnesses.

You are either going to need to find a decent used one in a salvage yard, build a new harness from scratch, or patch whatever needs repaired on the Jeep.

 

[Ralph77]

New pigtails might be the way to go.
Appears at least the NSS one for sure.
Googling for your Jeep with a 4.0, cause you don't say what engine, gives us this:

https://www.partsgeek.com/gbproduct...MI48Sa0r756gIVA49bCh3l7gpYEAQYAyABEgIogfD_BwE

Now is this right part? Not sure.
Also would this fix the problem? Not sure.
And are there other things that need to be fixed?
Basically because your mechanic did not point out to you exactly what the issues are you are going to have to crawl under there and figure it out.
Also if a pigtail would have fixed the NSS problem your mechanic should have known that buying something like this was possible.
So either it would not fix the problem, at least with the NSS, or you need to find a new mechanic.