Mr. India is a story about orphan Arun Verma, who spends his adult life raising orphan children in a struggling household. He faces financial difficulties and is unable to make ends meet.
International criminal and smuggler, Mogambo, wants Arun's house to store arms and ammunition, giving him a deadline to vacate. To protect his home, Arun decides to find a tenant named Seema Sohni, a local newspaper journalist, to occupy the top floor.
Mogambo's men target Arun and the children to force them out. Arun's dad's friend, Professor Sinha, introduces him to a gadget that makes him invisible. Arun uses this device to become invisible and fights back against Mogambo's men, calling himself "Mr. India".
As "Mr. India", Arun helps those facing injustice and becomes a hero to the people, although only Jugal knows his true identity. When one of Arun's children is killed and the others, along with Seema, are abducted by Mogambo, Arun must make a decision to save their lives and protect India.