[2] The film features an ensemble cast consisting of Bharath, Abhirami, Shaan, Anjali Nair, Pavithra Lakshmi in important roles.

The film's technical crew includes editor San Lokesh, cinematographers K. S. Kalidoss and R. Kannan, and music composer Jose Franklin.

[4] Rangaraj, a retired army officer shoots a young boy, Sudharshan, when he attempts to pluck mangoes from a nearby tree.

During the investigation, it was discovered that the bullet missed Sudharshan's corpse and to evade accountability, Rangaraj disposed of the gun in the Coovum canal, where it was retrieved by an unknown individual.

Savitri, a sanitary worker, and single mother, aspires to provide her transgender daughter, Karthi "Aarthi", with a medical education.

The hospital demands payment by the next day, but Raja refuses to ask his wealthy in-laws for help, citing self-respect, since they had earlier rejected him for their daughter.

In a desperate bid to secure the funds, Raja agrees to work for his former boss, thereby killing Kowsi, a social worker and communist thinker.

Actor Bharath who was last seen in Ippadiku Kadhal (2024) joined hands with debutant director Prasad Murugan for his upcoming hyperlink thriller film titled Once Upon A Time in Madras.

[5][6] Additionally, the director informed that a transperson was cast in the film for an important role, rather than making a male artist perform so.

[7][8] The technical crew consists of editor San Lokesh, cinematographers K S Kalidoss and R Kannan, stunt choreographer Sugan and music composer Jose Franklin.

"[13] Jayabhuvaneshwari B of Cinema Express rated two out of five stars and wrote "Once Upon a Time in Madras feels like a loaded chamber with no real firepower.