On our trip to Connaught Place, we spent a great deal of time searching for Nizam's. Our feet were tired, we were burning up in the hot sun & were close to giving up. Finally google maps came to the rescue & I found the place, hooray!
Nizam's has hallowed status in Delhi for their famous kathi kababs, a type of (North Indian) roll.
Sadly it was a big disappointment for me. Rude owner, bad / haphazard presentation, extremely oily rolls that weren't even that tasty (We tried Paneer & Mutton). What saved the day for us was the pitcher of lemon soda. It was nothing special, just lemon juice + soda + sugar is an ugly plastic jug. But we were parched, & it hit the spot!
Here's a picture of my dad very happy in anticipation of the rolls. He keeps talking of the famous kathi rolls he had many years ago in Nizam's Kolkata (not sure if it's related?) He said these didn't match up at all.
I really liked the advice at the bottom of the bill, though.