Rajinikanth was unwilling to star in the film. Vijay also rejected the movie as he didn’t want to do such a heavy subject as he felt he was a beginner at that time.
Kamal Haasan who was willing to do the movie asked him to postpone the shoot for 10 months as he was busy with the shooting of Hey Ram but Shankar couldn’t agree and decided to cast Arjun.
Silambarasan was cast in the lead role but rejected due to unknown reasons.
Shankar announced the project would feature Kamal Haasan and Preity Zinta and the film was titled Robot. Despite performing a photoshoot with Kamal and Preity, the project was shelved due to scheduling conflicts and budget issues in 2001
GVM initially approached Ajith Kumar and Vikram for the role without success.
The film was initially announced as Mirattal in March 2004 to be produced by NIC Arts and to feature Ajith Kumar and Asin in the lead roles. However, the project fell through for reasons unknown and then was revived with Suriya in the lead.
Ajith pulled himself out of the project after the film was shelved twice. Bala tried for the third time and finally managed to complete the project with Arya in the lead.
Suriya was impressed and accepted to work but after the first schedule, Suriya said Menon had been tinkering with the script for six months without any such progress and that he could wait no longer as he had committed to other films.
Mani Ratnam held a photo shoot for the film with Vikram and Manisha Koirala, but eventually did not choose Vikram as he was unwilling to remove his beard and mustache that he had grown for the production of another film during the period
The story was originally narrated for Vijay but rejected due to unknown reasons
Shankar wanted Kamal Haasan to play the lead role, but he refused because of the politics shown in the story and felt “it was not the right position to take on the subject”.
The role played by Kamal Haasan was initially offered to Rajinikanth but he rejected it due to unknown reasons.
Ajith rejected Saamy.