In "Kal Ho Naa Ho" the song is used during a little restaurant "makeover" montage in which a failing New York diner is turned into an Indian restaurant which immediately attracts all the customers away from the successful Chinese restaurant across the street.

Somehow... the lyrics to Chale Chalo were just a little too powerful for a restaurant transformation. Now that I understand a little more about "Lagaan" it all makes sense. ^.^