When I used Fuse to create a character that I want to use for a game. Now I need to parent the gun model to the hand in unity but the model is only
Does the model have a skeleton. You could parent the gun model under the wrist bone.
You need to tell Fuse to contact the Mixamo.com website to rig your model (add a skeleton). In your screenshot, colinRigWithWalk doesn’t have a skeleton. After you rig it, you should see a new skeleton hierarchy as a child GameObject.