Hi Scotty I need some help I’m helping a friend of mine fix his truck it’s a 99 ford Ranger 5 speed 2WD it’s having issues shifting the first time he told me he was thinking it was shifting linkage so I got under to look for it and had him for the stick shift around to see any movement I couldn’t see anything thought the part I was looking for was located on the side of transmission itself and it was I couldn’t find so he proceeded to tell me that when he shifts into 3rd gear it grinds and now it’s parked and can’t be moved so what’s the deal with this Ranger is it the Transmission or the Clutch

Pray it's the clutch since it doesn't move at all now. If you put in a clutch and it works good except for 3rd gear, then third gear would be worn too but you could live with that