The india level shape files have been sourced from:

These files were extracted from GADM version 1.0, in March 2009

GADM is a geographic database of global administrative areas (boundaries).

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. This only covers our contribution, not that of others (data provided to us).

Visit http://www.gadm.org for details

There are also geojson files in each folder.

Available here: https://gist.github.com/mukhtyar/9958903

Mumbai ward level maps have been provided by my friend S. The geojson file is also present in the folder

Chennai ward level maps have been provided by my friend S. The geojson file is also present in the folder

• Visualizing geojson files: http://geojson.io/
• Understanding the geojson format: http://maptimesea.github.io/2014/12/03/git-geojson.html
• Other resources https://github.com/tmcw/awesome-geojson#data

• Visualizing shape files and converting to Topojson or Geojson: http://www.mapshaper.org/

• Let's make a map by Mike Bostock https://bost.ocks.org/mike/map/