On Mouse Release weld help PleasE

If Two actors in region - mouse release on other actor... Is there something wrong in the placing of these blocks?

This is wrong on so many levels.
Last created actor is unknown and will cause problems. In this instance actor inside a region is actor X. You can make joints only between two different actors. Create attribute actor and then then asign actor inside region that attribute and then make a joint between that attribute and actor inside a region in another instance.
Also, not sure, but I'd swap for each <> if mouse. Seems more logical to be executed when mouse released

ok.
what if I have random actors on the stage, I place two actors in region Zero, and release mouse on actor z to create
weld between the two actors of a specific group that are in the region?
That is what I'm going for.

You're almost there. For each block is a loop that is executed as many times as the condition is met. If there are 2 actors in a region, this loop will be executed 2 times, and for each instance actor inside a region will be different. That's why you need to create an actor attribute. Then actor attribute = actor inside a region. You can also make a number attribute and increase each time a loop is executed and then make a condition if counter = 2 then you can make a joint between previously stored actor attribute to second actor in a region.

FYI: This works without an attribute

Yes, but it works only on Actors groups and is not optimised. But if it works and you're happy that's good