No a lawyer cannot represent a client if their license to practice has been suspended. A license to practice law is like a license to drive a car insofar as that if it is suspended you can no longer use it. This means that representing a client during the time of suspension is not allowed. To do so is illegal and grounds for disbarment. If you think that your attorney has a suspended license you need to contact the State Bar to confirm if this is the case and, if so, to report him or her.