He started his career with Mudra at the age of 23. His main passion had always been film making; after college, he even applied to the Madras Film Institute to do a course in direction. However, he did not like the panel that interviewed him, so he walked out. After this, he got into the Masters in Computer Application (MCA) course in a college directly opposite the film institute. He always liked computers, so he thought that he could do well in this course. After studying there for three years, he was thrown out in the last year because of lack of attendance. According to him, this was mainly because he played a lot of cricket and watched a lot of movies.
He saw an ad in the papers for Mudra and he remembered seeing it after Buniyaad. The ad asked people to send in 100 words describing who they were. His idol was Ramesh Sippy when he started his career; he wished to emulate him in advertising and got to meet Sippy only much later.
Balki's ideas have included Daag Achche Hain for Surf Excel, Jaago re ads for Tata Tea and the "walk when you talk" Idea Cellular advertising campaign. He has written and directed Cheeni Kum (2007), which starred Amitabh Bachchan and Tabu. His second feature film was the critically acclaimed and commercially successful Paa, (produced by Sunil Manchanda), released on 4 December 2009, starring Amitabh Bachchan, Abhishek Bachchan, and Vidya Balan. Paa is based on the life of a 13-year-old child named Auro (Amitabh Bachchan's character) suffering from a deadly disease known as Progeria. Abhishek Bachchan, who is the son of Amitabh Bachchan in real life, acted as his father in this movie.
Ilaiyaraaja, the noted Indian composer, is his favourite composer. Balki once commented, "My biggest inspiration has been Ilaiyaraaja's music; it was his music that got me interested in cinema in the first place."