Mankatha is a racy and adrenaline-rushing story of a Maharashtra police officer Vinayak Mahadevan (Ajith) who is suspended for helping a smuggler to escape from police encounter. He starts leading life in his own way. He falls for Sanjana (Trisha), daughter of an influential local goon Arumuga Chettiyar (Jayaprakash) in Mumbai. A tough cop Prithvi (Arjun) takes charge to end betting scandal in IPL cricket in Mumbai. Arumuga uses his links with dons in Mumbai tries to route through his old theatre, a cash of over Rs 500 crore to be used in betting. Sumanth (Vaibhav), a goon working for Arumuga Chettiyarplans to take away the booty with the help of his friends Ganesh (Ashwin), Mahanth (Mahanth), who owns a bar in Mumbai and Prem (Premji), a IIT graduate. Trouble starts when two of the team betrays them.