The students representatives at a meeting in IISc raised the possibility of a formal convocation with robes. Sometime ago, our learned minister Jayaram Ramesh said that these gowns are an anachronism a piece of our colonial legacy. Indeed, they may have come from European Universities, but where did the European Universities get them from? Do not look far, but read the address given by Mahmood Mamdani at the University of Johannesburg in 2010, which you can find here. He says, "...borrowed from the Islami madressas of the Middle East." and further that "..., modeled after the dress of the desert nomad, as the symbol of high learning."
Professor & Former Chairman,
Centre for High Energy Physics,
Indian Intitute of Science
Disclaimer: The views expressed here are strictly my own and my employer can in no way be held responsible for them.