They are both correct. Your vehicle placard(usually found in door jamb) will tell you what OEM size was on your exact unit. An automobile often has a couple of sizes available for different trim levels, option packages, etc. Both sizes you mentioned have an overall diameter within 1/2" of each other....hardly noticeable when payload, air pressure, tire wear come into consideration.
The 255/60-17 will be pitched to you as the "sportier" tire....while the 245/65-17 will be taller and more "utilitarian" according to tire sales sharks.
Have fun and be sure to pay CLOSE attention to price difference between the two selections.
-Phil