Step 1: Understand the body that made the decision.
The Constitution of India was drafted by the Constituent Assembly. This assembly also took on other important national tasks before the first Parliament was elected.
Step 2: Recall the timeline of India becoming a Republic.
India's Constitution was adopted on November 26, 1949, but it came into full force on January 26, 1950 (Republic Day).
Step 3: Identify the specific date of adoption.
The Constituent Assembly held its final session on January 24, 1950. On this day, they performed several key functions:
(Y) They adopted "Jana Gana Mana" as the National Anthem.
(Z) They adopted "Vande Mataram" as the National Song.
([) They elected Dr. Rajendra Prasad as the first President of India.
This was just two days before India officially became a republic.