India commemorates the day of 26th January as Republic Day. In 1950, on the very same day Constitution of India came into force. It is the same day when Declaration of Independence was promulgated by the Indian National Congress and this day were chosen to honor that event.
It is one of the three national holidays of India, including Independence Day and Gandhi Jayanti. Being a gazetted holiday all government offices and most businesses are closed on Republic Day.
The main parade takes place in the national capital New Delhi, at the Rajpath before the President who unfurls the national flag. Celebrations are also held in state capitals, where the Governor of the state unfurls the national flag.