To make Boman Irani (a Parsi) understand the character of a Punjabi property dealer better, the director showed him the real footage (captured on hidden cameras) of how Delhi property dealers behaved .
When Kamal Kishore Khosla went to meet Kishan Khurana for the first time, the spinning dolphin on Kishan Khurana's desk stops spinning for about one minute, but in the next scene it's still spinning.