Well, that depends on the size of your stock wheels,,,which will vary by model.
On a DII, you can run 265/75/16, which is about a 31" in BFG,,,, or a 285/75/16 which is about a 33", perhaps a hair under. Just make sure you have the right lift & clearance or you'll get rubbing & have stuffing problems. Either way you'll have some rubbing on radius arms at full turn. To properly run 285's off-road you'll need at least 3" of lift on a DII.
DIs are a bit different, perhaps someone can comment but the 265's don't seem to be a very good fit. I can't remember the right metric size, someone here will step in.
If you have 15" wheels you can simply find a 32" tire in a width appropriate to your wheel.