Which article of the Indian Constitution establishes Hindi in Devanagari script as the official language of the Union?

Article 343 of the Indian Constitution explicitly states that "the official language of the Union shall be Hindi in Devanagari script." This article also includes provisions for the continued use of English for official purposes for a prescribed period, initially set at 15 years following the adoption of the Constitution, though English continues to be used for various official purposes. For context, Article 342 addresses the designation of Scheduled Tribes, Article 344 pertains to the formation and recommendations of the Official Language Commission, and Article 345 grants states the authority to adopt their official language(s) for state-level administrative purposes.