Jalal1, the consultant that you visited obviously does not know what they are talking about. You do not need to be a registered nurse in Canada for you to start your application as FSW. Visit CIC-website and check the 38 occupational list that was announced last November 08, RNs are included here and they will be fast-tracked provided you meet the rest of the requirements.
Piece of advice, if ever you will continue with the application, do not utilize the services of the consultant that you visited, these are the type of consultant that will jeopardize your good chance to migrate to canada.