In order to see his little girl more often, a divorcee disguises himself as an old lady and gets a job as his own daughter's caretaker. A Hindi remake of the 1996 Haasan-starrer "Avvai Shanmugi".
Unfortunately the movie Chachi 420 is not yet available on HBO Max.
| Writing | Crazy Mohan | Original Story |
| Camera | S. Thirunavukkarasu | Additional Director of Photography |
| Camera | M. S. Prabhu | Additional Director of Photography |
| Production | Sab John | Line Producer |
| Crew | Raghuram | Choreographer |
| Directing | Kamal Haasan | Director |
| Writing | Gulzar | Dialogue |
| Production | Kamal Haasan | Producer |
| Production | Jhamu Sughand | Producer |
| Writing | Kamal Haasan | Screenplay |
| Production | Chandrahasan | Producer |
| Production | P.L. Thenappan | Executive Producer |
| Camera | Jehangir Choudhary | Director of Photography |
| Sound | Vishal Bhardwaj | Original Music Composer |
| Sound | Aditya Narayan | Playback Singer |
| Crew | Vikram Dharma | Stunt Coordinator |
| Art | Keshto Mandal | Art Direction |
| Art | Bidhan Guha | Assistant Art Director |
| Art | M. Prabhaharan | Art Direction |
| Art | Boban Koodaram | Art Direction |
| Editing | N.P. Sathish | Editor |
| Sound | Rekha Bhardwaj | Playback Singer |
| Sound | Hariharan | Playback Singer |
| Sound | Kamal Haasan | Playback Singer |
| Sound | Shruti Haasan | Playback Singer |
| Sound | Asha Bhosle | Playback Singer |
| Writing | Gulzar | Lyricist |
| Production | Aqeel Qureshi | Production Manager |
| Costume & Make-Up | Sarika | Costume Designer |
