The Chennai Corporation has expanded to 200 wards now and most of the data is available in the old boundary datasets. So if you want to do any analysis of data within the Chennai Corporation, you would need the boundary details.

Here is the shape file and the mdb file of the expanded Chennai with 200 wards.
MDB File & Shape File

Note: Convert the .txt file into .shp before importing. For some reason, we could not upload the data directly in .shp format. This is the raw edit, requires edge corrections. nevertheless a good start.