Interrogatories are a helpful tool for discovery. Interrogatories are written questions which focus on any information relevant to the case.All discovery must be conducted during the discovery period, which begins when the first initial disclosures are due and continues for 180 days. Initial Disclosures are due, under the rules, about 50 days after service of the suit. A party must make a complete response to each interrogatory. Texas Rules of Civil Procedure 197 governs interrogatories. The parties, or after adding or omitting one or more parties;. A party must make a complete response to each interrogatory.