Synopsis :
Mann is a story about Karan Dev Singh (Aamir Khan) who is a young flamboyant playboy, and uses every trick in the book to charm wealthy women, who will shower him with expensive gifts and support his extravagant lifestyle. There is only one problem though. Karan who is always looking for greener pastures, is already engaged to marry a billionaire's daughter to ensure a free flow of money for life. Karan is travelling from Singapore to Bombay aboard a ship to go back in his fiancee. On the same ship Priya (Manisha Koirala) is also travelling to Bombay, on her way to marry her fiancee.

Karan continues with his philandering ways and sets out to charm, and add Priya to his list of conquests. However, after being snabbed by her, he is enamored by her disarming nature and withdraws his advances, surprising even himself. Both Karan and Priya try to distance themselves from each other and sail back to their respective to-be spouses. But it's too late, cupid has struck and they are already in love with each other. In order to prove their love for one another, Karan and Priya decide to meet at a pre-designated place only after a period of 6 months, when they would embark on their life together.

But the struggle for the future begins now. karan, who is no longer under the graces of his ex-future father-in-law, for the first time would have to start earning a living. Priya, an orphan, indebted to her fiancee for being there for her feels obliged to go through with her wedding plans. Do they meet? If they do, do they unite? Will karan really change his ways? Does Priya have the moral courage to defy her fiancee's selfless love for her? MANN is a film about listening to your heart.