After receiving a mere 38.72% from Mumbai University, Harpreet Singh Bedi (Ranbir Kapoor) finds himself living with his grandfather, PS Bedi (Prem Chopra). Lacking the funds to enroll in a private MBA program, he takes a job as a salesman at AYS Computers. Here, Harpreet quickly learns that honesty is not the best policy. He faces ridicule, being branded a 'Joker Sardar,' and suffers mockery from both his superiors and colleagues. His desire to make a name for himself drives him to collaborate with four fellow employees: Girish Reddy, Koena Shaikh, Chhotelal Mishra, and Nitin Rathore, culminating in the creation of a fictitious firm dubbed 'Rocket Sales Corporation'.
Nitin is the sales manager, reporting directly to Mr. Puri, the CEO. While Nitin initially opposed hiring Harpreet, Mr. Puri recognizes his sales potential and brings him on board regardless. Koena, the attractive secretary, becomes a significant figure in their antics. During a field trip, Nitin reveals the underhanded tactics of the sales world. Girish is a shady service technician known for charging outrageous fees for minor repairs.
Harpreet's first assignment sends him to a major client, NCC, where a bribe is demanded. When he refuses, he is met with threats and ridicule from both Nitin and Puri, who subsequently spread word of his insubordination among the staff, turning everyone against him. Undeterred, Harpreet begins cold calling potential customers and secures an order for two PCs from an enterprising businesswoman named Sherana. Uncovering that AYS is overcharging clients, he decides to source his parts directly from Lalwani and sells the PCs under the Rocket Sales Corporation banner, with Girish helping to assemble the components.
Despite his success, Harpreet struggles with guilt and contemplates confessing to Mr. Puri. However, when Puri publicly humbles him in front of the NCC client, Harpreet resolves to teach Puri a lesson. He officially incorporates Rocket Sales Corporation with Girish, and when Koena, enraged by a lack of promotion from Nitin, decides to join Harpreet’s venture, they begin catering to clients disillusioned with AYS, providing attractive offers like 24-hour service and money-back guarantees.
As their orders increase, they hire Chhotelal, the AYS peon, as their fourth partner due to his expertise in assembling computers. Eventually, Nitin becomes aware of their scheme and confronts the group, attempting to blackmail them. However, Chhotelal, standing his ground, threatens to expose Nitin's fraudulent expense claims. Harpreet offers him an equal stake in return for securing orders.
As the business flourishes, Harpreet and Sherana develop a romantic relationship, complicating his life further. When Mr. Puri discovers the truth about Rocket Sales, he orchestrates their arrest to make an example of them. Harpreet is forced to sign away the brand name and agree to a non-compete clause for Puri to refrain from pressing charges. Ultimately, they all lose their jobs, yet Puri's actions backfire as Rocket's clients abandon AYS in droves, seeking the exceptional service they provide.
In a twist of fate, Puri—facing pressure from his own failing business—tries to entice Harpreet with a lucrative job offer, but Harpreet staunchly refuses. Puri is left humbled, acknowledging that his company cannot satisfy Rocket's former clientele. As a result, he returns the business to Harpreet, who reassembles his team and embarks on a successful new journey.
