The issue with Sahara is transparency and regulation, critics and regulators say.
For example, it does not always publicise its investment plan terms.
A newer scheme, Q Shop Plan H, which is built around the group's new initiative to sell household goods directly to consumers, promises returns of about 135 percent after 6 years, according to a term sheet that does not mention Sahara.
Some agents said they were asked to try and convert holders of the outlawed bonds to the new plan.
Asked if the details of the scheme banned by the court were explained to customers, a long-time Sahara employee in Uttar Pradesh said: "We don't have to explain all that. The depositor only wants to know how much he would be paying and how much he will get back on maturity."
The court ordered the money be repaid within 90 days, with 15 percent annual interest, prompting speculation over how Sahara will scrape that kind of money together.
Sahara responded with a rambling, full-page newspaper ad assuring investors their money was safe. It also condemned any suggestion it had raised any so-called "black money" or sought any undue favour from any authority.
"People cannot accept Sahara's super-fast growth. All along we have been getting beatings and beatings from all authorities, whereas we should be appreciated," it said.
Image: In this picture taken on February 14, 2004, India's then Deputy Prime Minister LK Advani (fourth right) is seen alongside Subrato Roy (third right) at his younger son Seemanto's (fifth right) the lavish multi-million-dollar wedding to Chandni Singh (sixth right) in Lucknow.