Single Bench of Patna High Court held as follows, regarding interrogatories and their usage.
From Para 13,
MS Ram Pravesh Rai Estate (P) Ltd. Vs Sri Rajesh Kumar Singh @ Munna on 12 Jan 201613. Now coming to floor, it is apparent that object and purpose of serving interrogatories is to enable a party to require information from his opponent for the purpose of maintaining his own case and for destroying the case of the adversary and as such, it not only shorten the trial proceeding, save time of the court, it also deliverance the party from expenses, consumption of time as well as burden to collect and produce evidences. Side by side, it should always be guarded in a way to prevent misuse. Furthermore, as is apparent, it should be confined to the facts which are relevant to the matters in question in the suit. However, under Order-XI Rule 6, 7 the grounds have been enumerated whereupon interrogatories could be refused.
Basically, it has been settled at rest by different judicial pronouncement as:-
(i) A party is not entitled to administer interrogatories for obtaining discovery of facts which constitute exclusively the evidence of his adversary‟s case or title.
(ii) A party is not entitled to interrogate as to any confidential communications between his opponent and his legal adviser.
(iii) A party is not entitled to execute interrogatories which would involve disclosures injurious to public interest
Other sources:
https://indiankanoon.org/doc/32984899/