Pritam works as a Book-keeper in an Export Import Firm and does not have a roof to live under. When he goes to search for accommodation, he runs into a friend, Jagdish, who takes him to a rooming house and lets him share one room with himself, Kavi Viyogi, and Hhimsen. The landlady has very strict rules for all her tenants to wit: No one is allowed to romance on her property. On a rainy day when Pritam goes to buy milk, he runs into a beautiful girl, Meena Sharma, and their umbrellas get entangled, and when freed get interchanged. He goes to look for her house and finds she lives with her maternal uncle, a music maestro of sorts, and Pritam enrolls himself in his class. Pritam and Meena continue meeting and fall in love with each other. When Meena's sister is about to get married, she travels to Poona and that's when Pritam finds out that her train had an accident and she has been listed as one of the dead. Heart-broken and devastated he is severely depressed, until his co-workers decide that he should go for a picnic and this does cheer him considerably. In this cheerful state he returns home and decides to carry on with life without Meena. It is then Meena returns back, quite very much alive, and finds that Pritam is not in a state of mourning but is enjoying life to the fullest. She decides to teach him a lesson that he will never forget. Watch what happens when the lesson commences and what impact this has on our care-free friend - who is currently wooing a dancer by the name of Edna Wong.

Inspector Arjun Singh, meritorious and honest, is assigned the duty of Inspector-In-Charge of a police station in a community that is rife with crime. Arjun soon brings law and order to this region, which bring him in the bad books of local politician Azghar Pandey, the Superitendent of Police, Surajpal Singh, and various other powerful and influential people. Arjun meets with Bharti, a woman forced into prostitution, and both get married. Then the forces of oppression owned and controlled by Azghar take over, Arjun is severelly beaten and is taken to a hospital that is governed by former convicted killer, Dr. Mathur, who is known for killing more patients than for curing them, and it is here that Arjun and the community will be put to test whether the truth and justice win or if harsh reality is death to the good people.

Siddharth "Sid" Mehra (Ranbir Kapoor) is the spoiled, carefree son of wealthy businessman Ram Mehra (Anupam Kher). A resident of Bombay, his only interest is to have fun with friends and to spend his father's money. Thus, he spends little time at college and is not prepared for the exit exams. His father however, not being aware of this fact, tells Sid it is time to join his company, which Sid reluctantly does only after his father tempts him with the promise of a new car.

Meanwhile, Sid meets Aisha (Konkona Sen Sharma) a woman from Calcutta, who is an aspiring writer. On their first meeting, they go out on a walk along the streets of Bombay. Sid shows her the city and takes her to Marine Drive by the sea. Sid tells her that one of the fascinating things of being in Bombay is its luscious monsoon. They seem to strike a chord instantly and a friendship ensues. Sid helps her to find (and furnish) her own apartment. She also lands a job with Mumbai Beat, (based on Time Out! Mumbai)[1] a hip magazine run by the handsome, sophisticated editor-in-chief Kabir (Rahul Khanna). On the eve of her 27th birthday Aisha invites Sid to her place because she does not want to be alone. When Sid tentatively explores moving their relationship beyond friendship, he finds that Aisha perceives him as boyish and immature. Despite feeling hurt, he maintains his friendship with her.
Their relationship intensifies when the exam results come out and Sid finds that he failed. His failure leads to a family fight that ends with him moving out of the house. With nowhere to go, Sid (who has never been on his own) asks Aisha if he can stay with her. Aisha is initially happy to have the company (although she clarifies that his stay is purely platonic). Eventually, however, Sid's bad habits revive themselves as he leaves her place a mess and makes the kind of demands on her that he is used to making on everyone. When she finds he has not eaten all day, Aisha is amused by the fact that Sid cannot cook and does not know how to feed himself. Over time, Sid learns that to survive in the world he has to begin cooking and cleaning. He has also realized he must work and Aisha helps him become a photography intern at the magazine she works for.

Vijay is a simple-minded widower who lives in a small rural town in India with his unmarried sister, Radha; his son; and his widowed mom. Radha is soon to be married to Sub-Inspector Raj. One day Vijay witnesses a killing of a young child by notorious bandit Bhagad Singh, and chides him. As a result, Bhagad and his gang severely beat him up, and only spare his life after Vijay's mom begs them to forgive him. But Lala Dayaluram hires Bhagad to ensure that Vijay and his family leave the town, and when they refuse Vijay is abducted, severely beaten and left for dead. An escaped convict and killer named Karan, who happens to be Vijay's exact look-alike, sees the unconscious Vijay, and decides to assume his identity, stabs him, and throws him to his death from atop a cliff. Karan then goes to live with his family. The motive for Karan to live here is merely to hide under Vijay's name until the police give up their manhunt for him. No one really notices the change in Vijay. Karan starts to frequent the nearby brothel run by Kammobai, and soon realizes that he can make a lot of money by selling young women to her. His first target that he intends to lure to Kammobai is none other than Radha, Vijay's sister. This is just one of the destructive methods he intends to employ in his new identity and there is no one who can dare to suspect nor stop him.

Sushil Kumar lives a middle-class lifestyle in Riksapur in the District of Bhagalpur, located in a country called Mundustan, along with his widowed mom, Kamini, an unmarried sister, Shobha, and his pregnant wife, Sunita. Shobha falls in love with a wealthy man named Kumar, introduces him to her family, gets their approval and gets married. Shortly thereafter she disappears, and the Kumar family realize that Shobha has been abducted by her husband, who belongs to a gang of of women-kidnappers. Sushil is determined to find her whereabouts, gets a job with the Police as a Sub-Inspector, does his work honestly and diligently and is publicly honored. Thereafter he is assigned by CBI Officer Sangram Singh to a secret mission to locate and apprehend smugglers, thieves, and women abductors, which can only be done after he dons the guise of jailed gangster Kanwar Lal, his look-alike. Sushil accepts this assignment in the hopes of being re-united with his sister - not knowing that he is putting not only his very own life but also the lives of Sunita and Kamini in serious danger.

Wealthy practical prankster Sunita falls in love with a lowly truck-driver, Anand, much to the chagrin of her dad, Sohanlal; mom; Chacha; and Mama, who publicly humiliate Anand. She defiantly decides to elope with him, and asks him to meet her in their family bungalow in Koofri. But Anand informs her family and comes to know that her dad has been re-located abroad for medical treatment. The rest of the family ask him to accompany them to Koofri. They will soon be mystified when Sunita arrives and refuses to recognize anyone including Anand himself.