Can the President appoint more than one acting Chief Justice at a time?
No, the President cannot appoint more than one acting Chief Justice at a time. The context states that "When the office of Chief Justice of India is vacant or when the Chief Justice is, by reason of absence or otherwise, unable to perform the duties of his office, the duties of the office shall be performed by such one of the other Judges of the Court as the President may appoint for the purpose." The use of "such one" implies a singular appointment.