A group of friends- a crime reporter Abhay (Randeep Hooda), a medical intern Maya (Kangana Ranaut), a computer Engineer Goti (Neil Bhoopalam) and a mechanic Kalim (Angad Bedi) form a vigilante gang called "Ungli", after their friend Ricky (Arunoday Singh) is refused to grant justice. They take a dig by punishing the corrupt officials, while making their videos and uploading it on the social networking sites. Their antics have made them a hero in public, but have also reduced them to criminals under the Police radar.

An honest Police officer ACP Ashok Kale (Sanjay Dutt) is handed over the "Ungli Gang" case, who appoints an undercover cop Nikhil (Emraan Hashmi) to bring out the real faces behind the masked notorious gang. Soon he enters the gang, introducing himself as a law student. But then he comes to know the real motive of the "Ungli Gang" and starts believing in their ways. Thus, now he is left with the query whether to continue his undercover mission assigned by Kale or join his hands in real with the gang to bring the corrupts on track.