After singing 'Aati Kya Khandala' for Jatin-Lalit in Ghulam, Bollywood's Mr. Perfectionist Aamir Khan is all set to lend his voice to Dhoom 3 theme song. For this composer Pritam Chakraborty has been clearly instructed by producer Aditya Chopra to compose a tune, which will match Aamir's character in the movie. According to reports Pritam has also been asked to complete all his other assignments by June this year, so he can give all his attention to 'Dhoom 3'.