My son hired an attorney for his case and just found out that the attorney license is suppended what can he do

Two things. First, he needs to contact the Tennessee Supreme Court's Board of Professional Responsibility www.tbpr.org/ as soon as possible to discuss the situation.  Second, he needs to contact an experienced employment attorney to discuss his case as soon as possible. If he has not filed his claim in court yet, then time is running out.  If he has filed in court, then the Court must be notified and he must comply with all the other deadlines and rules the court has issued in his case.