If he dings you for them on the report, you’ll need to buy them before you return or pay a penalty about 30 days after they take the car back. With that said, the repair estimates they give seem to be very reasonable. My wife sideswiped a Rogue 1 month before inspection. I had an estimate done at a body shop for 2200.00. The lease end inspection estimated it at 488. We turned the car in and would’ve paid the penalty (less than my collision deductible, and no need to get insurance involved), however the dealer ended up buying it for their inventory, so we owed nothing.
Incidentally, they will waive 500 in damages should you lease another Nissan or Infiniti, which would include the tire estimate the inspection company would give you. You didn’t mention if you are, but if you are planning on it, You might want to see what the inspection report says a set of tires costs. If they estimate 4 new tires will cost 600, and you buy a new Infiniti or Nissan, you’d only owe 100.
To answer your question though, if the inspection says you need tires, you do have a chance to buy them before you turn the car in. Take note what their estimate is first and cross-shop a set of tires to see which is cheaper…the tires or the estimate. If you end up replacing them, I think you need to get another inspection done to avoid paying the penalty though, or you call a number and fax over receipts proving you bought tires. That I can’t recall.