The film is inspired by the real life ordeal of 64-year-old Professor Siras( played by Manoj Bajpayee), who was suspended by the Aligarh University for being homosexual. He was ostracised by the society at large and subjected to physical and psychological torture for his sexual preference. Rookie journalist Dipu Sebastian( Rajkummar Rao) is the man who sees him for what he really is. Aligarh is their journey.