(2)After such an application as aforesaid and the rejection thereof wholly or in part or after the lapse of six months without an answer to such application or a decision thereonpublished by the Government, it shall be competent to the person interested and deeming the rule or order contrary to law to institute a suit against the State for a declaration that the rule or order is unlawful either wholly or in part. The decision in such suit shall be subject to appeal; and a rule or order finally adjudged to be unlawful shall by the Government be annulled or reversed or so altered as to make it conformable to law.