235-245 and depending on width-you should be good for on/off road.
now for the second # r75 is usually stock normal and you should not have any trouble.
if you want a wider tire you get R70, R65, I wouldn't go any further.
If you get 235R70/16 this should work- you might have some scrubbing on sharp turns or turning into an entrance with a sharp incline. Also depends on tread style. But this is what you have to put up with if you want a better looking ride. And better clearance- but it will turn your tracker from Bad to bad ass! I have heard that fairly aggressive 31s will fit nicely, that's what i heard- take it for what its worth. I also remember what the #s on the tire stand for. 235/70/15, the 235 is how tall the tire is and the 70 means -70% of 235 is the width. I may have gotten it backwards: Also remember "white walls on the inside, and raised white letters mount out, doesn't help with slip streaming but makes it look good".
Now if you can translate this, you are way ahead me (I couldnt understand it) (good Luck and happy times)