Republic Day is a national holiday in India, when the country marks and celebrates the date on which the Constitution of India came into effect on 26, January 1950, replacing the Government of India Act as the governing document of India and thus, turning the nation into a newly formed republic.

The history of Republic Day
The Indian Constitution came into effect on 26 January 1950, which declared India's occurrence as an independent republic. January 26th was chosen as the date because on this day in 1930, the Indian National Congress revealed Purna Swaraj, the declaration of India's independence from the colonial rule (26 January was chosen as the day to announce India becoming a republic as in 1929 on the same day the Indian National Congress denounced colonial rule and proclaimed Purna Swaraj, “complete freedom from the British”.

This completed the country's transition into becoming a Sovereign Republic)

Parades, distribution of sweets in schools, speeches and cultural dances mark the celebrations

The Republic Day parade is held in the capital, New Delhi and is organised by the Ministry of Defence.

Commencing from the gates of the Rashtrapati Bhavan (the President's residence), Raisina Hill on Rajpath past the India Gate, this event is the main attraction of India's Republic Day Celebrations and lasts for three days.
The Republic Day parade showcases India's Defence Capability, Cultural and Social Heritage.

Different regiments of the Indian Army, Indian Navy, and Indian Air Force with their bands march past in all their finery and official decorations. The President of India who is the Commander-in-Chief of the Indian Armed Forces, takes the salute.
Contingents of various para-military forces of India and police forces also take part in this grand annual parade.