Section 153(a) in Civil Court Rules of the High Court of Judicature at Patna
(a)Letters of Request issued by a Court in India for the examination of witnesses in foreign countries should be forwarded to Government for transmission through the regular channel. Such Letters of Request must be issued in English, and must be accompanied by a list of interrogatories, in English, to be put to the witness, and also by a translation, in the language of the Court in which it will be executed, of the letter of Request itself, of the interrogatories and of any other documents which accompany the letter. In cases in which the parties on both sides agree to be represented at the examination of the witness in the Foreign Court, the Court issuing the Letter of Request may, if it thinks fit, ask that the agent of the parties be permitted to put such further questions to the witness in examination and cross-examination as they may be advised.