He's a simple middle class boy, from a simple Delhi family. But his dreams are far from simple. Not only is his icon Jim Morrison, he wants to be an iconic rockstar himself. Little realizing what havoc a real heart break can cause, he's naive enough to believe that if he gets his heart broken, he will suffer enough anguish required to become a great musician. But then he meets Heer and he's drawn like moth to a flame to this cool and classy beauty, which seems absolutely unattainable. He finally gets that heart break he's wanted so much; and the torment of that unfulfilled love unleashes in him the musician that he always wanted to be...but also extracts a terrible price... Ranbir, in his most challenging role as he metamorphoses from a wannabe Delhi geek to an iconic, charismatic and pioneering rock star, who's edgy, angst ridden music is but a reflection of his anguished soul.
Nargis Fakhri as Heer Kaul
In an astonishingly layered debut performance, Nargis is the stunning, classy, campus diva, who has the world at her feet, but prefers to keeps everybody at arm's length. But then a nerdy boy earnestly requests her to please break his heart and she's undone. For beneath that prim and proper demeanor, there's a carefree soul, wanting to break free of all conventions... to let go in abandonment...to ride on the wild side... to do things she's never done before. She realizes that only this odd ball character called Janardan, who she's renamed Jordan has the key to unlock her wilder side. She also knows that time is ticking away and soon she will be imprisoned into boring domesticity forever.
Shammi Kapoor as Ustad Jameel Khan
The iconic star makes his farewell appearance as the wise Ustad who is the first to recognize that Janardan's formidable talent cannot be caged; he needs to be set free as a musician to explore and invent his own music.
Aditi Rao Hydari as Sheena
She's the journalist who's followed and chronicled Jordan's graph from struggling artiste to rock star. She thinks she knows him best, but hasn't even come anywhere close to understanding the demons that drive him on and on.
Kumud Mishra as Khatana
He's the college canteen manager, the only friend Janardan can bare his soul to. He's the one friend Janardan can count on, the only friend who gives Janardan unconditional support through good times and bad.
Piyush Mishra as Dhingra
The owner of Platinum Music Company is a shrewd and astute businessman. Rather than nurturing talent, he prefers to misuse it to maximize his profits.
Shernaz Patel as Neena Kaul
Mrs. Kaul wants nothing but the best for her daughter and tries her best to understand the special bond between Heer and Janardan.
Janardan, born and brought up in the very middle class locality of Pitampura in Delhi, has a larger than life dream - of being a rockstar like Jim Morrison! But all he gets from his reluctant audience is ridicule and humiliation. He's at his wit's end, when he realizes that all musical stars; all artists in fact, have one thing in common. And that is tragedy. They all have tragic lives. They have all suffered painful heartbreaks to become what they are. Alas, there is no pain in Janardan's life - it is an oasis of peace. Unless he does something drastic, he will never become a rockstar. Heer Kaul is the undisputed diva of the college campus - beautiful, talented, arrogant, rich, and unavailable. She has broken many hearts. . Janardan hopes she will break his heart too. He sets out to woo Heer with the sole object of getting his heart broken. Rock star is the journey of a boy - who leaves behind Janardan to become Jordan; who traverses the highs and lows of life - from simple naivete to tortured soul, from the pleasure of unaffected friendship to the torment of unrequited love, from the campus in Delhi to the international stage. He ultimately gets all that his heart has ever desired but in the process shatters / loses his heart forever...