Industrial Disputes (Central) Rules, 1957
33. Expenses of witnesses
Every person who is summoned and duly attends or otherwise appears as a witness before a Board, court, Labor Court, Tribunal or National Tribunal or an arbitrator shall be entitled to an allowance for expenses according to the scale for the time being in force with respect to witnesses in civil courts in the State where the investigation, enquiry, adjudication or arbitration is being conducted.