Writer: Siddharth Malhotra
Cast: Rani Mukerji as Ms. Naina Mathur
Naisha Khanna as Young Naina Mathur
Shiv Kumar Subramaniam as Principal of St.Notker’s
Neeraj Kabi as Mr. Wadia
Supriya Pilgaonkar as Sudha Mathur, Naina’s mother
Sachin Pilgaonkar as Prabhakar Mathur, Naina’s father
Hussain Dalal as Vinay Mathur, Naina’s brother
Harsh Mayar as Aatish
Sparsh Khanchandani as Oru
Ivan Sylvester Rodrigues as School Principal, who didn’t offer job to Naina
Benjamin Yangal as Ashwin
Kalaivanan Kannan as Raghu
Vikrant Mitun Soni as Killam
Rohit Suresh Saraf as Akshay
Vikram Gokhale as Mr. Khan
Asif Basra as Shyamlal
Riddhi Arora as Sunidhi
Suprio Bose as Mr. Pereira
Jannat Zubair Rahmani as Natasha
Naina Mathur has a B.Ed. and M.Sc. but cannot obtain a teaching position due to her Tourette syndrome which causes uncontrollable sounds likened to hiccups. Despite failing for five years, she is supported by her mother Sudha and her younger brother Vinay. Her father Prabhakar divorced her mother, and Naina’s relationship with him is consequently strained. Also, Prabhakar sees teaching as low paid and wants her to take a job that she can cope with even with her “miserable condition”.
Naina eventually receives an offer to teach at the prestigious St. Notker’s School which she had applied to five times before. When asked why she was so persistent, Naina explains she studied there and was inspired by Mr. Khan, a principal, who believed in her and announced that she would never be expelled for being different. Naina’s confidence impresses the school and they assign her to 9F, a new class section. In reality, the school was desperate as all other teachers had failed to control the class. Naina finds the students are unruly, misbehaved and visibly different. Shyamlal, the school’s peon, discloses to her that the 9F students come from a nearby slum and were admitted to fill the government-prescribed quota for the underprivileged.
On the first day, Naina’s students imitate and mock her. She decides to teach them interactively, determined to show resilience. The students prank her with liquid nitrogen which explores, shattering the windows. Naina prevents a mass expulsion by saying that the prank required planning, and if that can be guided, the class has potential. Wadia, teacher of class 9A, dislikes the 9F students. His class comprises academically excellent prefects. Naina asserts that her students will earn prefect badges.
The school’s annual Science Fair project is assigned to 9A, who are prevented from mingling with 9F by Wadia. They yearn to experience the interactive experiments 9F have but Wadia dismisses them as inferior to textbooks. Meanwhile, 9F warms up to Naina and wholeheartedly participates; she teaches them to be brave in pursuing knowledge and to realize their individual strengths. Aatish, the sole student who remains cold, secretly sabotages 9A’s project. This is discovered by Wadia and the Principal decides to expel 9F. Again, Naina prevents this by promising that they will pass their exams, but is unable to prevent their suspension from attending school till then. Dejected, she tells them they have shattered her attempt to help them. Aatish’s classmates help him realize his mistake and he publicly expresses regret.
All of 9F studies diligently. Shyamlal supplies Aatish copies of the wrong question paper so they would fail, but when he presents them to his classmates, they refuse to cheat and he gives up on the idea as well. Results prove Naina’s promise as the 9F students pass. However, the class is accused of cheating as Shyamlal confesses to supplying papers, and the Principal decides to expel them during the prefect pinning ceremony. Akshay, one of Wadia’s students, reveals that he bribed Shyamlal into supplying the wrong question papers and realizes that 9F did not cheat. Wadia takes to the stage and announces that he wrongfully tried to fail the students. He then applauds Naina’s transformative teaching and asks her to pin the prefect badges to her students, who ranked first. She later tells him that she doubts that he didn’t bribed Shyamlal. Mr. Wadia smiles and says that he also doubts she didn’t caused a liquid nitrogen explosion. With the combined efforts of 9A and 9F, the Science Fair project is rebuilt and wins the competition. The chemistry between 9F and 9A students became better and the conversation gap became less.
The film shows Naina’s last day at St. Notker’s where she has served for 25 years and has been Principal. As she walks out of the school, the school’s students bid farewell. The last to happily bid her adieu are the students of 9F who are now successful adults.