However, that appears to be a mistake or mis-report: the original screenplay credits Rahul Kumar as Millimetre.

Rahul Kumar — “Millimetre” from 3 Idiots

Name: Rahul Kumar
Famous Role: Millimetre (Manmohan, aka “MM”) in 3 Idiots
Nationality: Indian
Occupations: Actor, model, singer
Active Since: Childhood / early theatre; film roles from mid-2000s onwards Wikipedia

Early Life & Career

Rahul Kumar started acting very early — he was involved in theatre from a young age. Wikipedia
As a child actor, he appeared in The Blue Umbrella (2005) as Tikku and in Omkara (2006) as Golu. Wikipedia
His most iconic role came in 3 Idiots (2009), where he played Manmohan, better known as Millimetre, the helpful campus assistant who does small chores for students.
Over the years, he has continued acting in films and web series. For instance, he appeared in the Amazon Prime series Bandish Bandits.

Rahul Kumar recently made news for marrying Keziban Doğan, a Turkish woman, on 4 May 2025.
Their love story is quite cinematic: Keziban first reached out to him after watching 3 Idiots — she messaged him saying she loved his performance as Millimetre.
The wedding combined Hindu and Christian rituals to honor both their cultural backgrounds. Telegraph India

In 3 Idiots, Millimetre is more than just a helper — he is a sympathetic, grounded character who quietly supports the main students (Rancho, Farhan, Raju).
One of his iconic lines (or how he’s remembered): “Millimetre ab Centimetre ban chuka hai” — a reference to time passing and his growth. OdishaTv
His performance left a lasting impression, and many fans still fondly associate Rahul with this role. MensXP

Apart from his 3 Idiots fame, Rahul has continued acting in various projects: films, theatre, and web series. Wikipedia
He appears to keep a relatively low but steady profile; media coverage often highlights him in the context of his 3 Idiots role and his personal life.

There is some confusion around “Millimetre” casting: a Times of India headline once claimed Dushyant Wagh is Millimetre.
- However, that appears to be a mistake or mis-report: the original screenplay credits Rahul Kumar as Millimetre.
Rahul’s recognition from 3 Idiots has stayed strong: even years later, people refer to him by his character name and talk about how he’s “grown up.”