[1] Rangan was selected for a workshop by the Advertising Agencies Association of India (AAAI), Mumbai which led to him having a stint as a copywriter with J. Walter Thompson in Chennai.

[5] His first review was of the Hindi film Dum, published on 30 January 2003 in the Madras Plus supplement of The Economic Times.

[6] Rangan has authored two books: Conversations with Mani Ratnam (2012), wherein he interviews film director Mani Ratnam on the perspectives of his films,[7][8] and Dispatches From The Wall Corner: A Journey through Indian Cinema (2014),[9] which he describes as a "panoramic view of Indian cinema".

[11] Rangan made his debut as a dialogue writer with Kadhal 2 Kalyanam,[12] which never saw a theatrical release.

[15] Rangan wrote the English narrative for the 2014 play Meghadootam: The Cloud Messenger.

The citation given to him by the jury of the 53rd National Film Awards reads, "The Award is presented for intelligent and reader-friendly reviews of popular cinema with a depth of understanding of the form, a discernible passion for the medium bulwarked consistently by a knowledge of the trends and touchstones of global cinema.

"[2] In 2013, Arul Mani of Tehelka described Rangan as "far and away the most intelligent writer we have in India when it comes to cinema".