Following the announcement of the project, tentiatively titled as Akbar, Shriya Saran was rumoured to be the heroine, following her successful role in Sivaji: The Boss. However due to differences, Saran was ousted from the project due to her limited callsheets, as she had to fly to and from America where she was then shooting for her Hollywood film, The Other End of the Line. However other indications claimed that Saran was ousted from the project due to her involvement in Indiralohathil Na Azhagappan, in which she appeared in an item number; which Ajith Kumar was unhappy with due to previous feuds with the lead, Vadivelu of that film. Reports indicated that Parvati Melton had replaced Saran, but later denied it signalling that she was not approached. Suhani Kalita was announced as the second heroine of the project, but was later removed due to unknown reasons. Several Bollywood heroines including Deepika Padukone, Bipasha Basu, Katrina Kaif, Ayesha Takia, Ileana D'Cruz, Tanushree Dutta and Sneha Ullal were linked to the role, as well as reports that Shriya Saran would reprise the role after making up with Ajith. The role eventually was given to Katrina Kaif, who was set to make her debut in Tamil films with Aegan, however she later opted out due to callsheet clashes. It was announced that Nayantara would play the role of the heroine in the film, following her role opposite Ajith in Billa. Furthermore it has been indicated that Namitha, Mumaith Khan and Rakhi Sawant will all appear in an item number in the film. In February 2008, it was confirmed that Navdeep would play a role in the film as well as Suman, who will appear in a villainous role. Malayalam actor, Jayaram will also play a role in the film, which will be co-produced by actor, Arun Pandian. Nassar and Suhasini Ratnam were selected to play the roles of the parents of Ajith, whilst Raju Sundaram's elder brother, Prabhu Deva was given a chance to make a cameo appearance in the film as a dancer. Supporting actors M. S. Baskar and Sriman also play roles in Aegan, as does newcomer model Piya, who appears as the ladylove to Navdeep. Yuvan Shankar Raja was signed on as the music composer whilst debutant Arjunan was given the opportunity to be the cinematographer for the project and Milan, who did the art direction for Billa, renews his association with Ajith in the film.
