Hi Raman,
SITI Broadband levies NO installation charges at this point.
We use CastleNet CBW209D1 for up to 50 Mbps plans (DOCSIS 2.0) and CBW383G1 for the 100 Mbps plan (DOCSIS 3.0)
These modems are not easily available in the open market and even if they are, they would be relatively expensive.
Hope this answers your queries 🙂