Section 11(4)(b) in The Arbitration And Conciliation Act, 1996
(b)the two appointed arbitrators fail to agree on the third arbitrator within thirty days from the date of their appointment, [the appointment shall be made, on an application of the party, by the arbitral institution designated by the Supreme Court, in case of international commercial arbitration, or by the High Court, in case of arbitrations other than international commercial arbitration, as the case may be] [Substituted by Act No. 33 of 2019, dated 9.8.2019.].