More than 25,000 policemen and paramilitary forces are guarding the streets of Delhi and snipers have been deployed on high-rise building.
Thousands of policemen have also been deployed in other cities and towns.
The parade will be attended by the president and the prime minister with the chief guest, Thai Prime Minister Yingluck Shinawatra.
Indian-administered Kashmir, which has seen a long insurgency against the Indian rule, is observing the day as "Black Day".
A multi-layered security ring has been put in place at Rajpath [King's Avenue], where President Pratibha Patil will unfurl the Indian flag and take the salute of marching contingents, news agency Press Trust of India reports.
Reports said 160 closed-circuit cameras have been installed between Rajpath and Red Fort, the route of the parade.
Anti-aircraft guns have been placed at several places and helicopters are hovering over the parade route.
Security has been stepped up in Kashmir where police and paramilitary forces have been deployed in large numbers at Bakshi Stadium, the venue of the Republic Day celebrations, in Srinagar city.
Reports said 40,000 policemen are keeping vigil in the financial capital, Mumbai, which has seen several high-profile militant attacks in recent years.
Security has also been stepped up in the north-eastern state of Assam where several insurgent groups are active.
Thousands of policemen have also been deployed in other cities and towns.
The parade will be attended by the president and the prime minister with the chief guest, Thai Prime Minister Yingluck Shinawatra.
Indian-administered Kashmir, which has seen a long insurgency against the Indian rule, is observing the day as "Black Day".
A multi-layered security ring has been put in place at Rajpath [King's Avenue], where President Pratibha Patil will unfurl the Indian flag and take the salute of marching contingents, news agency Press Trust of India reports.
Reports said 160 closed-circuit cameras have been installed between Rajpath and Red Fort, the route of the parade.
Anti-aircraft guns have been placed at several places and helicopters are hovering over the parade route.
Security has been stepped up in Kashmir where police and paramilitary forces have been deployed in large numbers at Bakshi Stadium, the venue of the Republic Day celebrations, in Srinagar city.
Reports said 40,000 policemen are keeping vigil in the financial capital, Mumbai, which has seen several high-profile militant attacks in recent years.
Security has also been stepped up in the north-eastern state of Assam where several insurgent groups are active.
