With the baseline as 'The system is so corrupt that you can only ridicule it', the film UNGLI starts off on a high. The film opens with an old man and his young daughter waiting at the Pension Office and being bullied by the 'babus' working in the office. The old man gets a stroke and lands up in a hospital where his poor daughter narrates her dilemma to the doctor, which is overheard by Maya (Kangna Ranaut), who is works in the same hospital. She informs her friends Abhay (Randeep Hooda), Goti (Neil Bhoopalam) and Kaleem (Angad Bedi) that they got their 'first case'. The team, then, covers their faces in masks and kidnap the 'babus' at night. As a part of their plan, they strap the 'babus' with 'time bombs' and make them run in an empty stadium. Not just that, they also inform the cops and media about the same. In no time, their antics are all over the media channels and they become famous as the 'UNGLI' gang. Slowly the gang starts expanding their operations and putting up the videos of punishing the corrupt on the internet and win the hearts of the masses. The cops, however, are not happy about this and the Police Commissioner (Raza Murad) gives the case to anhonest police officer Ashok Kale (Sanjay Dutt) to solve. But, when Kale fails to catch the gang, he realizes that he will need to use someone who thinks like them to work against them. That's when he decides to put a police officer Nikhil (Emraan Hashmi) on job. Emraan, who happens to be the son of a late cop and a close friend of Kale, is not interested in working with the police and hates the system and it's functioning. He is however notorious in his ways of operating and hence Kale hands him the responsibility of catching the UNGLI gang. Nikhil takes up the job and does his own tricks in punishing the corrupt and takes credit for it pretending to be an UNGLI gang member. The sudden entry of Nikhil wakes up and shakes up the original gang. With a few hints that Nikhil throws at them through the 'trademarked' video messages, the gang tracks him down and eventually he joins them. However, Nikhil soon realizes that the gang is not wrong in their approach towards cleaning up the society. But, due to a certain situation and circumstances, he gets torn between his duty (as a police officer) and his friendship with the UNGLI gang members. Kale, on the other hand, too waits to seek answers from Nikhil as the pressure keeps building on him to catch the notorious gang. Amidst all of this, a situation gets cropped up where all these characters are faced with a situation where they have to either accept the corrupt society for what is it or else fight back by risking their own lives.
Whether Nikhil will for go his duty as a police office and betray the trust of the UNGLI gang by having them arrested, will Kale manage to get his hands on these gang members, will the gang manage to achieve what it have set out to do... is what which forms the rest of the story.