It offers multiple range speed from 512 Kbps to 100 Mbps. It can be best alternative to BSNL.(Railwire is an undertaking from(Ministry of railway)
Uses optical fibre for connectivity so most probably there should not be issues related to speed.
Service and support is satisfactory as I have personally used it for few months.
Charges are the poor side of this ISP and somewhere you might feel dissatisfied. You can find much more cheaper and better combination with private ISP.
You can find this ISP on those place where private players are not available.
https://railwire.co.in/tarrifs-and-plans.php