Question is not completely clear.
You can use almost any tires on the tow vehicle. Tires for use on the trailer is a different question. Usually you will find that the GAWR (Axle load capacity) is high enough to require ST type tires.
Your RV has a Vehicle Certification label AKA Tire Placard, on it (outside, driver side, toward the front) that gives you the GAWR and tire size and the recommended inflation which is usually the same as the inflation number molded on the tire sidewall.
If you want to change type or size tire on the RV you MUST select tires that have equal or greater load capacity than the OE tires when inflated to the same level.
You can learn more about tires, loading and inflation on my RV tire Blog. www.RVTireSafety.net