Produced by Inder Kumar, the film stars Arun Vijay in a dual role along with Vidya Pradeep, Tanya Hope, and Smruthi Venkat.

In the film, police officers try to solve a murder case involving lookalike suspects arrested on the basis of a pictorial evidence.

Thadam was released theatrically on 1 March 2019, opening to critical acclaim with praise for Arun Vijay's performance and the writing.

Ezhil, is a civil engineer from IIT Madras, while his lookalike Kavin, is a gambling thief who deceives people along with his sidekick Suruli.

The next day, Kavin frees Suruli by paying his debt and wins Ananthi's trust by returning her money and telling her the truth.

However, as the investigation of Akash's murder proceeds, a selfie clicked by a couple nearby is found with either Ezhil or Kavin in it.

The forensic expert informs Malarvizhi about a hair sample recovered from the crime scene and how it doesn't match anyone else in Akash's home.

Ezhil is finally revealed to have murdered Akash for drugging, kidnapping and raping Deepika to death out of his childhood lust.

[15] Thinkal Menon of The Times of India rated 3.5 out of 5 stars stating "Thadam has an intriguingly written flow of events which begins from the pre-interval point and maintains the suspense factor till the end".

[16] Srinivasa Ramanujam of The Hindu stated "Thadam by Magizh Thirumeni is an effective murder mystery involving identical twins".

[17] Writing for Film Companion, Baradwaj Rangan rated it 2.5 out of 5 stars stating "The cinematographer keeps throwing in slightly angled frames, which give the sense of a dual reality: one normal, one skewed.

[19] S Subhakeerthana of The Indian Express rated 3 out of 5 stars stating "At first glance, Thadam, inspired by real events, comes across as a pretty straightforward urban thriller.

[20] Writing for Firstpost, Sreedhar Pillai rated 3 out of 5 stars stating "Thadam is an out-and-out Arun Vijay film.

[21] Anupama Subramanian of Deccan Chronicle rated 3.5 out of 5 stars stating "Barring couple of dull moments, Thadam is a well-written engrossing thriller worth a watch".

[22] Kavitha Muralidharan of The News Minute rated 3 out of 5 stars stating "The film has a deceptively simple storyline but the treatment makes all the difference".