Definition: A flash mob (or flashmob) is a group of people who assemble suddenly in a public place, perform an unusual and seemingly pointless act for a brief time, and then quickly disperse, often for the purposes of entertainment, satire, and artistic expression. Flash mobs are organized via telecommunications, social media, or viral emails. Source: Wikipedia
Ranking of the flash mob among the universities are available in most popular Bangladeshi Online Radio Station HelloDhaka.
The Ranking could be found in the following link.