Roll No. 21 (or Roll Number 21) is an Indian animated series produced and aired by Cartoon Network India. It first premiered on November 14, 2010. The series is a modern take on Krishna and Kansa's rivalry. In this version, Kansa has re-incarnated as Principal Kanishk, the principal of Mathura Anath Ashram (Mathura Orphanage and School) where he is cooking his evil plans to take over Mathura and then the rest of the world. He is supported by his various minions and demons.
The series is known for its visually appealing animation and witty storyline. Also the series takes place in a fictional school and so it supposedly connects with kids of same age. Thus, making it really popular among Indian kids.
In this series, as Kanishk hatches plans to take over the world, he is also joined by an incarnation of Lord Krishna who appears in the school as Kris, a little boy who is a student in the orphanage. And so in each story, we see Kanishk coming up with an evil plan while Kris will do anything to stop him.