All EB-5 investments have to be at risk. Any statement in the offering documents guaranteeing the return of the investment funds to the investor will not be in compliance with the US immigration rules. You may analyze those EB-5 Regional Center projects that have had a history of immigration success over the past several years in respect to the foreign national investors obtaining there Permanent Residency.
One of the main components of the EB-5 Immigrant Investor Program is the "at risk" requirement for the investment. There is no certainty on a return on your investment because, like any other investment, your capital will be at risk.