Mr. Natwarlal (1979)

Natwar is just a young boy when his beloved older brother and caretaker, police officer Gridharilal (Ajit), is framed for bribery by sinister criminal mastermind Vikram (Amjad Khan). When he grows up, Natwar (Amitabh Bachchan) creates a secret identity for himself, posing as a powerful and mysterious underworld figure named Mr. Natwarlal, determined to slowly but surely exact vengeance on Vikram.