Rock On!! begins in Mumbai, with the rock band Magik, in 1998. Joseph (Joe) Mascarhenas (Arjun Rampal) is the lead Guitarist who feels the necessity to prove his worth as a musician. Aditya Shroff (Farhan Akhtar) is the lead singer who rebelled against his well-to-do family to play music. Rob Nancy (Luke Kenny) who plays keyboards and Kedar Zaveri a.k.a. KD/"Killer Drummer" (Purab Kohli) comprise the remainder of the band. After a competition is announced by Channel V, they decide to enter, as the winner will be offered an album contract and at least one music video.

Rock On was well received by a number of critics. Subhash K. Jha gave Rock On a rave review. He states: "Seldom has a film blended the music of life into the fabric of a film with such seamless expertise. Rock On!! is that rarity where every component character and episode falls into place with fluent virility." Nikhat Kazmi of the Times of India gave it four stars and argued, "if you really want to see how Bollywood has matured and come of age, then here's the perfect litmus test. For Rock On is a film that not only breaks new ground in terms of its subject matter – now when has desi movielore ever tackled something akin to Hollywood's That Thing You Do — it creates a whole new EQ (emotional quotient) for mainstream cinema." Khalid Mohamed, of the Hindustan Times gave the film three and a half out of four stars and describes it as "hard candy." He also states that "the performances are of the highest order". Manish Gajjar of the BBC gave Rock On!! four out of five stars and describes it as "an enthralling watch, with entertaining moments to make you smile. Predicted to be a cult movie for many years to come, it truly deserves the Bollywood awards this year! A must-see whether you are a rock fan or not!" Taran Adarsh of Bollywood Hungama gave Rock On!! four out of five stars and states: "Put your hands together for one of the finest films of our times. Put your hands together for a Director who pulls off a challenging subject with élan. Put your hands together for the actors who pitch in superlative performances." Kaveree Bamzai of India Today called Rock On "refreshing" and "surprisingly quiet and thoughtful."

A sequel to the film, Rock On 2, was released on 11 November 2016. Akhtar, Rampal, Kohli, Desai and Goswami reprise their roles from the first film.