While I donot know about your consultancy,what i have understood is that the employment based greencard (e.g. EB2 and EB3) is for a future employment. One does not have to be in US to start/get the EB3 visa. As long as your employer is willing to provide the prevailing wage approved by DOL, you may get EB3. But make sure the one who promised you the Eb3 is genuine.