Where in any case the Federal Court require a special case to be stated or re-stated by, or remit a case to, or order a stay of execution in a case from, a High Courtin a Federal State, or require the aid of the civil or judicial authorities in a Federal State the Federal Court shall cause letters of request in that behalf to be sent to the Ruler of the State, and the Ruler shall cause such communication to be made to the High Court or to any judicial or civil authority as the circumstances may require.