To minimise the noise from terrestrial sources the interferometers must be built in a place where earthquakes are least likely. Turns out that the Deccan plateau in India is one of the most seismically quiet zones in the world.
With collaboration of Indian Seismic Survey. A list of the most seismically QUIET zones of India were identified. After detailed study using data from ISRO's CARTOSAT which can map the earth surface with the special resolution of 2.5 meters, a few sites were short listed. The contribution of IISER Kolkata in the site analysis is notable. Later a detailed map and specification of the most favourable constructions was prepared by TATA Consultancy Services.