S Shankar is coming up with the highest budget Indian film ever, which was likely to be titled as Robot earlier. This film has surpassed the budget of the Bollywood high budget film Blue (2009).
However, Shankar could not continue with the English title due to the present tax exemption of the government. So, some other alternative titles were suggested such as Iyandhiran or Iyandhira. Later in September 2008, it was confirmed that the title of the movie would be Enthiran .
There was a lot of confusion regarding the casting of the film. In July 2007, Shah Rukh Khan was signed as the male lead and the producer of the film. But later in October 2007, both Shahrukh and Shankar called off the project due their personal conflicts with the script. Talks were going on to sign either Ajith Kumar or Amir Khan to do the film but on January 2008, Rajinikanth was confirmed for the male lead.
Several heroines including Priyanka Chopra, Deepika Padukone, Asin Thottumkal, Trisha Krishnan, Sriya Saran, Priyamani and Nayanthara were approached for the female lead. Later, Aishwarya Rai was confirmed for the female lead with a huge fee of 6 crores, thus Rai becoming the highest paid actress in India.
Danny Denzongpa was signed for the lead antagonist and comedians like Santhanam and Karunas were signed for some cameo roles. Manoj Bharatiraja, son of the noted film-maker Bharatiraja, would be the assistant director. Both Manish Malhotra and Mary E Vogt will work on the costumes. Music is composed by the maestro A.R.Rahaman. Stan Winston Studios will be doing the animatronics and the industrial light and Magic will be working on the visual and the special effects of the film.
Sun Pictures has bought the film from the previous producers Eros International for 165 crores. Talks are going on with the HBO to release the film in the West with English subtitle version.
The first schedule of the film has started on 8th September 2008 at Peru following the locations of United staes, Brazil,Goa, Himachal Prades and Chennai. Scenes featuring a robotic conference, including Rajinikanth, Aishwarya Rai, Santhanam and Karunas were shot in the SSN College of Engineering and in the Vellore Institute of Technology, where over 400 students were used as extras.