Vaseegaran, played by Rajnikant is a scientist, who has created and android robot named Chitti, the first of its kind with the help of his assistants Ravi and Siva. He then asks them to commission the robot into the Indian Army. The robot has also helped his girlfriend Sana, played by Aishwarya Rai to clear her medical exams by cheating and also protect her from goons. His mentor Bohra has tried creating similar robots for a terrorist group but hasn’t succeeded so far.
He makes Vaseegaran give a demonstration to the Artificial Intelligence Research and Development (AIRD) Institute but fails when the robot comes to stab Vaseegaran on Bohra’s command, proving that the robot is a danger in the Indian Army. He tries to makes changes in Chitti and asks for some time. Later Chitti falls in love with Sana and they come to know about it. Sana tells Chitti that they are only friends and nothing more. Chitti is heartbroken and deliberately fails another evaluation by the AIRD. Furious at this behavior Vaseegaran chops Chitti to pieces and dumps him into a landfill. Chitti assembles himself while Bohra inserts a 2.0 version red chip into him making him aggressive and non-empathetic.
Chitti causes destruction in the city and many people lose their lives. He discovers that he can reproduce and asks to marry Sana, but she refuses. There is a long ensuing battle between the robot army and the cops and eventually Vaseegaran captures Chitti and removes the red chip. He is then sentenced to death for creating a destructive robot and causing so much damage but in his defense he shows the court the footage of Bohra putting the red chip in Chitti. Eventually Bohra gets arrested. The movie is directed by S. Shankar and produced by Kalanithi Maran. The music is composed by A R Rahman.
