The words Kaccha Limbo denotes a child who is not mature enough. The movie follows the trials and tribulations of 13 year old Shambu. His friends in school ostracize him for being obese calling him names. Despite his school problems, Shambu does have a loving and caring family. He does not seem to relate to his step father, who seems to have a highly sympathetic attitude. He has crush for a girl, who does seem to despise him for his looks. He continues talking to her as an anonymous another person on phone.

Things take a turn for worse when he accidentally damages another student's video camera, for which he is asked to pay damages. On the same day his forgery of his parent's signatures in the school diary is found out. He runs away from home and befriends few slum children.

The power of friendship and deep understanding is revealed by one of the slum children he befriends. Shambu is listened to by this special friend, despite his looks, and then things take a turn when Shambu tries to save the life of this friend, who sadly dies.

The beautiful moral of this film would be not to judge somebody by their looks, but rather to understand the vast personalities people possess.