| Director | Siddharth P. Malhotra, Sidharth Malhotra |
|---|---|
| Genre | comedy drama |
| Runtime | 116 min |
| Country | India |
| Budget | ₹20 crore |
| Box office | ₹209.7 crore |
Naina Mathur, a Bachelor of Education and Master of Science, aims to become a teacher, but is repeatedly rejected as she has Tourette's syndrome, which causes her to make uncontrollable sounds likened to hiccups. Despite failing for 5 years, she is supported by her mother, Sudha, and her younger brother, Vinay, while her father, Prabhakar, sees little potential in the idea and expects her to take up a banking job. Naina eventually receives an offer at St. Notker's School to teach class 9F. Once she is employed as a teacher, however, she realises that the school was desperate to find a new teacher for 9F, as all other teachers had failed to control the class. Naina finds that the students are unruly, misbehaved, and visibly different. Shyamlal, the school's peon, informs her that the 9F students come from a nearby slum and were admitted only to fill the government-prescribed quota for the underprivileged after a previous municipality school on the St. Notker's football ground was closed due to mounting maintenance costs.
On her 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 explodes, shattering the windows. Naina prevents a mass expulsion by stating that the prank required planning, and if that can be guided, the class has potential. Wadia, the teacher of 9A, dislikes the 9F students. He informs Naina that his class comprises academically excellent prefects, but she assures him that her students will earn prefect badges as well. The school's annual science fair project is assigned to 9A. Meanwhile, Naina teaches her students to be brave in pursuing knowledge and to realise their individual strengths. Aatish, the sole student who remains cold towards Naina, sabotages 9A's science project. This is discovered by Wadia, and the principal decides to expel 9F. Again, Naina prevents it by promising that they will pass their exams, but is unable to prevent their suspension from attending school until then. Dejected, she informs them that they have shattered her efforts to help them.
Aatish faces ridicule from the rest of 9F and decides to apologise to Naina, and all of the 9F students study diligently. Shyamlal then supplies copies of the question paper to Aatish so that they would be able to cheat. When he presents the papers to his classmates, they refuse and he gives up on the idea as well. After the exam days, they pass but are accused of cheating when Shyamlal confesses to the plan, and the principal decides to expel them during the prefect-pinning ceremony. Akshay, one of the 9A students, reveals to Wadia that it was he who had bribed Shyamlal to supply the copies of the "wrong" question paper to 9F students, and Wadia realises that 9F students did not cheat. At the ceremony, Wadia announces that he wrongfully tried to fail the students and applauds Naina's teaching, requesting her to pin the prefect badges to her students who ranked first. After the ceremony, 9A and 9F put aside their differences and work together on a new science fair project which wins first place. The film ends with Naina's last day at the school after serving for 25 years, retiring as the school principal, as her former 9F students, who are all now successful, reunite with her.