Bones are needed to deform the geometry of an imported model. Your geometry has remained in its original position.
It is easier for you to export the model from TOR. with the bones and weights already included. The bones will allow you to deform the mesh in Blender, and the vertex groups (with their associated weights) can be renamed to match the vertex groups used in KOTOR.
If importing bones with vertex groups is not possible:
1. Create a skeleton and bind it to the mesh.
2. Deform the mesh using this skeleton so that the arms and legs are in the same positions as those of the KOTOR model.
3. Rename the weighted vertex groups so that they match the vertex groups of the KOTOR model.
4. Apply (save) the mesh modifier and delete the skeleton.
5. Rename the UV map of the imported model to "UVMap."
6. Join the objects using Ctrl + J. Select the mesh of the imported model first, then the mesh of the KOTOR model, and press Ctrl + J.
7. Enter Edit Mode and delete the KOTOR model mesh.
8. Export the model.
It’s better to use the original hands. Getting the weight settings right is incredibly difficult.
If I happen to work on something like this in the near future, I’ll post step-by-step screenshots.