(6) The appropriate Government or the specified authority may, either on its own motion or on the application made by the employer or any workman, review its order granting or refusing to grant permission under sub- section (3) or refer the matter or, as the case may be, cause it to be referred, to a Tribunal for adjudication: Provided that where a reference has been made to a Tribunal under this sub- section, it shall pass an award within a period of thirty days from the date of such reference.