Code of Civil Procedure, 1908
86.Suits against foreign Rulers, Ambassadors and Envoys.-
(1) No Ruler of a foreign State may be sues in any Court otherwise competent to try the suit except with the consent of the Central Government certified in writing by a Secretary to that Government:
Provided that a person may, as a tenant of immovable property, sue without such consent as aforesaid a Ruler from whom he holds or claims to hold the property.
(2) Such consent may be given with respect to a specified suit or to several specified suits or with respect to all suits of any specified class or classes, and may specify, in the case of any suit or class of suits, the Court in which the Ruler may be sued, but it shall not be given, unless it appears to the Central Government that the Ruler-
(a) has instituted a suit in the Court against the person desiring to sue him, or
(b) by himself or another, trades within the local limits of the jurisdiction of the Court, or
(c) is in possession of immovable property situate within those limits and is to be sued with reference to such property or for money charged thereon, or
(d) has expressly or impliedly waived the privilege accorded to him by this section.
(3) No Ruler of a foreign State shall be arrested under this Code and, except with the consent of the Central Government certified in writing by a Secretary to that Government, no decree shall be executed against the property of any such Ruler.
(4) The preceding provisions of this section shall apply in relation to-
(a) any Ambassador or Envoy of a foreign State;
(b) any High Commissioner of a Commonwealth country; and
(c) any such member of tile state or retinue of the Ruler, Ambassador or Envoy of a foreign State or of the High Commissioner of a Commonwealth country as the Central Government may, by general or special order, specify in this behalf, as they apply in relation to the Ruler of a foreign State.