Hindi cinema has its share of films in which children play an important part. And not just as the childhood version of the adult who plays the lead. Sometimes (Dhool ka Phool, Bandish) as unwanted. More often (Do Kaliyaan, Andaaz, Detective, Ek Hi Raasta, Laajwanti) as the means of bringing together two adults in a romantic relationship, or trying to hinder that relationship.
Less often, but I think often with more impact, children play the lead role: the film is about children, and the adults are mostly peripheral. Boot Polish and Diya aur Toofaan fall into this category. As does Naunihaal, about a little boy who sets off to meet Jawaharlal Nehru.