There are a lot of questions on SO asking a way to show region boundaries in google maps. The answers say it is not possible unless we specify the boundaries manually as polygon coordinates.
If that is the case then how are these websites showing the regions:
Now commonfloor has an area id (in its url) which means that it may have the boundaries in a database somewhere and is using it to draw the polygons. So may be they are not getting the data from google. But, zenify is doing something different. It's website loads these pngs from google which actually form those bounadries - eg. this - it is the top left part of the boundary of the entered location. We can see more of these files being loaded in the network tab of chrome development tools. How exactly is this kind of boundary mapping achieved without figuring out a way to get region boundary coordinates?
Also, if it is definitely not possible, and these websites are using some tool to map/get coordinates of Indian regional boundaries, what are those tools?