I doubt if the Ranger has the weight carrying capacity for much of truck camper, but you have to compare the TC weight with the specs for the particular year and configuration of the truck. All Rangers are not alike in their specs. 4 cylinder vs V6, suspension options, etc. make a big difference
Also, as far as I know, all Rangers are short bed trucks (6 ft instead of 8 ft). Will the camper fit in a short bed?