Assuming you're trying to connect some mount. Go to INDI Control Panel --> Your Mount Tab --> Connections Tab --> You will see System Ports here, select one and try connecting.
Click the Apple icon in the upper menu, at the top left of the screen and select "About this mac..."
Then push the button "System information" (or somthing similar, my OSX is in spanish)
In the Hardware section find USB item. The you will find all your USD devices, including your usb adapter.