Are they the Riing Plus fans? If so, you will need to purchase Thermaltake's TT Sync Controller, if you want to use Asus Aura to control the fans.
I believe any of their fans and LED strips that have the 9-pin USB 2.0 style header can be used on the sync controller. If you are talking about the regular RGB Riing fans I don't think you will be able to control them with anything but the controller they came with.