I'm looking to purchase 16" x 7 wheels for a ITr , the car will be dropped with one finger gap all around , what would be the lowest offset I can use without rolling the fenders or adding camber

 

+35 would be best any lower and you're in bs hella flush territory and please don't do that to an itr

 

I found a set of wheels +33 offset so I guess they won't fit with no fender mods

 

+33 is only 2mm farther out than +35, so you should be okay if +35mm does not require any fender rolling. Tire size may also be a factor aswell.

 

I would suggest staying with a 205 tire on that 7" wide wheel. So on that note, as others have already said, +35 is a safe common size, and 2mm really won't make much of a difference at that height. You can also help any "rubbage" with some negative camber.