[1][2] Born into the Mukherjee-Samarth family, Mukerji dabbled with acting as a teenager by starring in her father Ram Mukherjee's Bengali-language film Biyer Phool and in the social drama Raja Ki Aayegi Baaraat (both 1996).

[12] At age 18, following her mother's suggestion that she pursue acting on an experimental basis, Mukerji accepted leading roles in the social drama Raja Ki Aayegi Baaraat, Khan's second offer to her, and her father's Bengali film Biyer Phool, both of which were released on the same day in October 1996.

The role was originally written for Twinkle Khanna, but when she and several other leading ladies rejected it, Johar signed Mukerji on the insistence of Khan and the filmmaker Aditya Chopra.

[31][32] By 2000, Mukerji wanted to avoid typecasting as a "standard Hindi film heroine" and thus decided to portray more challenging roles in addition to the archetypical glamorous lead.

The film was a partly fictionalised account of Mahatma Gandhi's assassination and Mukerji played a Bengali school teacher who is raped and murdered during communal riots in Calcutta.

[36] Having only portrayed glamorous roles thus far, she was challenged by Haasan's insistence on realism and to appear on screen without wearing make-up; she believed that the experience changed her approach to acting.

[4] The controversial subject matter of Hey Ram led to poor box office earnings, but the film was critically acclaimed and selected as India's official entry to the Oscars.

[47] In Bas Itna Sa Khwaab Hai and Nayak: The Real Hero, films that failed to gain a wide audience theatrically, Mukerji played the love interests of Abhishek Bachchan and Anil Kapoor respectively.

[50] Mukerji began collaborating with Yash Raj Films in 2002, when the company cast her in two productions: Mujhse Dosti Karoge!,[51] a romantic comedy co-starring Hrithik Roshan and Kareena Kapoor, and Saathiya, a remake of the Tamil romance Alaipayuthey.

[53] The BBC wrote that "Mukerji plays the character of a middle-class girl with great conviction",[58] and Udita Jhunjhunwala of Mid-Day added that "her expressions and acting are understated in a role that fits her like a glove".

"[67] She won the Best Actress award for her starring role as Rhea Prakash in Kunal Kohli's Hum Tum (2004), a romantic comedy about two headstrong individuals who meet at different stages of their lives.

[70] The Hindu found Mukerji's portrayal of Rhea to be "self assuredly competent" and Tanmaya Kumar Nanda of Rediff.com wrote, "Rani is her usual collected self, changing into the many hues of her character with the ease of a chameleon".

[1] Her first film role that year was opposite Amitabh Bachchan in Sanjay Leela Bhansali's Black, a drama about an alcoholic man who dedicates his life to teach a blind and deaf girl how to communicate.

[41][66] Mukerji received another Best Actress nomination that year at Filmfare for her work opposite Abhishek Bachchan in Bunty Aur Babli, which marked her fifth collaboration with Yash Raj Films.

[97] Mukerji turned down an offer from Mira Nair to star in the English film The Namesake, choosing instead to reteam with Karan Johar in Kabhi Alvida Naa Kehna (2006), a drama about infidelity.

[102][103] Following the failure of Baabul, Yash Raj Films cast Mukerji in Siddharth Anand's family drama Ta Ra Rum Pum in the role of a racing driver's (Saif Ali Khan) wife and the mother of two.

"[107][108] The drama Laaga Chunari Mein Daag from director Pradeep Sarkar starred Mukerji as a young woman who is forced to moonlight as a prostitute to fend for her family.

[120] In a scathing review, Khalid Mohamed criticised Mukerji's choice of roles and wrote that "she's one-dimensional, either darting full blast smiles or tetchy scowls.

[124] She continued to collaborate with Yash Raj Films, taking on a starring role opposite Shahid Kapoor in the romantic comedy Dil Bole Hadippa!

[139] Greater success came for her portrayal of Roshni Shekhawat, a mother grieving the death of her child,[140] in Reema Kagti's psychological thriller Talaash: The Answer Lies Within.

[145] Despite poor box office returns,[146] Bombay Talkies met with critical acclaim, particularly for Johar's segment; Tushar Joshi of Daily News and Analysis praised the subtlety in Mukerji's performance.

[158] Inspired by Brad Cohen's autobiography Front of the Class, the film tells the story of Naina Mathur, an aspiring teacher suffering from Tourette syndrome who must prove herself by educating underprivileged children.

[157] In a mixed review, Anna M. M. Vetticad of Firstpost wrote that she "lifts Hichki every time she is on the scene, bringing empathy and charm to Naina's character without at any moment soliciting the audience's pity.

"[160] It earned ₹2.33 billion (US$27 million) worldwide, a majority of which came from the Chinese box office, and its success led Mukerji to express an interest in working more frequently in the future.

The Indian Express wrote that Mukerji is "in command right through as she works to a script which pushes her to the fore at every given chance", but Rahul Desai of Film Companion criticised her for overplaying Roy "as more of a Dhoom franchise character" than a cop.

[176] Reviewing the film for Screen Daily, Namrata Joshi dismissed its melodramatic tone, adding that "most disappointing is an otherwise reliable Mukherji being far from effective in her shrill and showy turn".

[197] In 2010, Mukerji performed at a concert in the Army Stadium of Dhaka, Bangladesh with several Bollywood actors including Shah Rukh Khan, Rampal and Ishaa Koppikar.

[199][200][201] Mukerji was all set to make her appearance at Cannes Film Festival, 2011 with Sabyasachi Mukherjee and Karan Johar, but later opted out due to her father's ill health.

[215] In 2014, Mukerji attended a charity dinner on child trafficking hosted by the British Asian Trust in London, where she was felicitated by Prince Charles for raising awareness on the issue through her work in Mardaani.

[1][221][222] As part of a career analysis, Sukanya Verma noted that after making an unconventional debut in films, Mukerji oscillated between success and failure for a few years before achieving "the status of a star, performer and showgirl".