Hi Sritama,
There are various PDF docs published here apart from the maps.
Some of them would be holding the population stats you're looking for.
Annexure 5 seems to have wardwise totals. I'm not sure if that's the population numbers or voters count.
Some online pdf-to-excel converters or Tabula / Excalibur tool should help make that into excel. (If you get it done and proper, pls share, I'll try to include that metadata in the shapefiles)
In case you're also looking for the shapefiles of the wards,
Also published on Datameet's maps github alongwith prior years' wards: