Tire Size

Hello everybody, I am looking to upgrade my tires on my 2015 Polaris Rzr 900s. I would like to know what is the biggest tire size you guys are running without doing any other suspension upgrades. I would also like to get the best tire for all kinds of riding. We like rock crawling, mud, and water. We are looking for a overall good tires. We ride in Northeast Pennsylvania. It is very rocky and hard terrains.
Thank you,
John