Several states, including Tamil Nadu, Kerala, Bihar, Odisha and Assam also celebrated the occasion.
Governors of each state hoisted the national flag on the occasion in the presence of dignitaries from all walks of life.
Delhi is under a ground-to-air security cover in view of the Republic Day celebrations.
Thousands of armed personnel are keeping a tight vigil across the city and in border areas of the city to ensure a smooth passage of the celebrations. (ANI)