I'm assuming you're referring to a viral video or a specific episode of "The Kapil Sharma Show" featuring Khan Sir, a popular educator and YouTube personality.

Khan Sir, whose real name is Faizal Khan, is a well-known educator and YouTube personality in India. He gained popularity for his unique teaching style and entertaining educational videos. His videos often feature him explaining complex concepts in a simple and humorous way.

After conducting a quick search, I found that Khan Sir did appear on "The Kapil Sharma Show" in one of the episodes. The episode featured Khan Sir in a comedy sketch where he played a humorous role.