This doesn't only happen at Google India. I have seen them in many SERPs over the last years, targeting several different countries. It seems to be a relatively easy job to obtain databases with business address information, write a script around it and slap ads on it.
Google provided this option to enhance the search by narrowing it down to the exact location or near by location. But, people are utilizing it to dominate the niche market by promoting their chain of business centers/outlets. This is done in majority by already well-established brands who doesn't want to provide space for other smaller competition in getting businesses.
[edited by: phranque at 8:39 am (utc) on Jun 22, 2010] [edit reason] TOS #13 [webmasterworld.com] [/edit]