Land was assembled by the govt for the sites. Your instinct is right, though. Assembly of land often took a long time and this was one of the key reasons why project implementation periods were long. It is worth noting that even today many state/local govts in India continue to assemble land and allocate it for different uses, such as infrastructure development and housing for low-income families. Several questions remain, however, regarding the most effective ways of delivering land or housing -- at scale -- in a manner that can also reach lower-income families. This blog and the (forthcoming) paper on which it is based are one contribution to that discussion. Many thanks for your excellent comments!