Can fema enforce marshals law using FEMA camps?

No, the term 'marshal law' means the imposition of military forces, FEMA is not a military force. FEMA is not trained or armed to enforce marshal law. If private citizens are hindering a FEMA operation, they may request the services of the National Guard or other military or police agency to assist. A request for the use of the National Guard must be deemed a 'Congressionally sanctioned national emergency or war'. FEMA can only request, Congress must sanction.