Vidhu Vinod Chopra's Mission Kashmir stars Sanjay Dutt as a moustached Pathan BSF soldier, called Khan. He is married to, the national award winning actress, Sonali Kulkarni. In the line of his duty he accidently kills a Muslim family in Kashmir. The whole family is wiped out apart from their young son played by Hrithik Roshan. When Hrithik Roshan realises that Sanjay Dutt is responsible for the death of his family, he thinks of how he can avenge the death. He knows he is too young and weak to avenge their death yet, so when he realises that Sanjay Dutt and his wife can't have kids, he plans it so, he gets himself fostered by them as they see him as helpless needy orphaned child.
Hrithik lives with them until he grows up, without them suspecting of his real intentions of killing Sanjay and his wife like Sanjay did to his family. But Hrithik knows he can't do it on his own and within him hate builds up for the Indian government too, under who's orders Sanjay wiped out his family.
So he decides to obtain help of Jackie Shroff, a terrorist leader in the mould of Osama-bin-Laden. Jackie Shroff is more than pleased to help especially when he realises that he is the foster child of Sanjay Dutt who is the biggest enemy of the BSF Army and who frequently foils his plans. So still without Sanjay and his wife suspecting, he gets more and more involved with terrorists!!
So with their help, he plots how he can destroy & kill Sanjay and his wife and do some major damage to the Indian army in Kashmir in the bargain.
This his now his Mission along the way until he meets Preity Zinta, a Kashmiri Hindu girl, whom he falls in love with.
How he goes about the rest of the mission and if he succeeds is the rest of the story of Mission Kashmir!!