India, Sept. 10 -- For two days this weekend, Delhi will become the centre of an extraordinary diplomatic operation, with world leaders, high-security convoys and thousands of officials and journalists converging on the capital for the 18th BRICS Summit.

India will host leaders and delegations from 11 BRICS member countries and 10 partner nations on September 12 and 13, prompting a city-wide security and logistical exercise stretching from Indira Gandhi International Airport to Bharat Mandapam and the hotels where the visiting dignitaries will stay.

Behind the scenes, Government agencies are working to choreograph everything from the arrival of special aircraft and movement of motorcades to hotel security, media access and secure commun...