In Lagaan, all of the people in Bhuvan’s village do not necessarily get along. When the British want to impose a much higher tax on Bhuvan’s village, he comes up with a plan to play a cricket game versus the British. Though the people of the village aren’t friendly with each other before the game came along, their sense of nationality comes to the forefront so that they can work to defeat the British. Nationalism is basically a sense of pride in the place you live. People can have a sense of nationalism for the same place without living the same life as those around them.
There are people of different ages, from different classes, and different religions all come together to support a common cause. They probably would not be able to get along in any other setting except for this one. Their sense of nation and nationality comes out when there is a promise of no tax if they win the cricket game. No taxes would not only benefit each person individually, but the whole entire village as a whole.