The company's full name is Sahara India Pariwar, or family.
Roy, 64, refers to himself as the guardian of the world's largest family, and espouses a philosophy of "collective materialism".
At its headquarters in Lucknow, staff greet visitors by putting their right hand to their chest and saying "Sahara Pranam".
Pranam is a respectful version of hello.
Roy, often photographed wearing a black necktie and vest over a white shirt, is based nearby at the showpiece Sahara Shaher, a sprawling gated complex of low white buildings and lawns where he lives and where the group holds an annual mass wedding for 101 couples who could otherwise not afford it.
Starting with capital of Rs 2000 in the late 1970s, Roy built Sahara into a giant that, according to its website, had assets of more than $21 billion as of April 2011.
Roy is often described as a billionaire but he is not on the Forbes list of rich Indians.
Sahara's website says no dividend has been paid for 34 years and no profit has been taken out of the company.
From its north India base, Sahara has become a cashed-up global investor in hotels, sports and entertainment.