before you import any geometry model (ydd) you have to import an associated .yft file first, so you get a full skeleton. In most of cases, you should rename the imported branch to .global so every following import you do will reuse the skeleton .skel from .global branch. In such a scenario, you should get a properly rigged model imported and bind to the skeleton. If you export from such a setup (geometry .mesh models in one branch and a .skel inside .global branch), you are likely to get all components rigged in game.

if your issue relates to a geometry you alter or change, then the above is a pre-condition to get everything up right, but not the only steps to take care of.

Good evening, im trying to change the shirt on a ped and the head/hair seem to rig just fine but the shirt and pants dont seem to rig properly and turns out as in the picture I provided below.