How is this clip suppose to be on here it’s a th400 trans and it’s for the actual shift cable itself

 

Goes just about where you are holding it, between the bracket on the Trans and the rounded cable.....slides between the 2 and provides pressure to hold the cable in place.

 

I’m pretty sure that the side you’re holding to camera gets flipped around(to face forward in the car)
Thats the mating surface that pushes against the bracket and not the collar of the cable.

Just wedge it in a little and then tap it home with a hammer.
-peter

 

Look at how the front brake caliper soft line mates to the hard line at the frame bracket. That same (or similar) retention clip resides there too.

 

This pic shows which side the clip goes on. You can just see the corner. The 90* tab points out opposite the bracket facing the front of the car. It allows the ability to grasp with vice grips or similar tools for removal/installation. I usually tap them into place with a small ball peen.