Is the gunclip equipped on jetfire in this picture? Thanks

 

No it is not and that jetfire is also missing a few armor pieces

 

well, how can he hold the gun like that without gun clip? is there any other holes on his arm that you can plug the gun into?

 

I think he's just holding it in his hand but the pic is an odd angle so it's hard to tell.

 

Either the clip is there and we can't see it for some reason, or the gun is sticking into the groove between his forearm and arm (the inside of his elbow).

 

As far as I remember (I guess I should try) the gunclip and armor can't be attached to the arm at the same time. He's just holding the gun in his hand on this picture. The angle is easy to achieve, the lower arm can turn around.

 

Hmm, seems like you can attach it to the arm armor piece.
http://www.seibertron.com/toys/gallery.php?id=453&size=0&start=75