2) More than 10 - Airtel, Excitel, Den, Spectranet, MTNL, Vodafone, Jio, Idea, Tata, Tikona, MTS (and a few others?)
3-4) Highest bandwidth is 150 Mbps, costs around 1500 INR a month (~$22). No data cap that I know of.
5) Cheapest is definitely Jio. 1.4 GB a day at 4G speeds (mobile broadband) and after that unlimited at 64kbps. Costs 400 INR (~$6) for 84 days.
6) Service for Jio is spotty. Service for that 150 Mbps plan (Spectranet) is top notch.
7) Yes, MTNL is a govt entity. Their plans have no data caps but are very expensive as compared to others.
8) Definitely like my ISP. I get 100 Mbps from Excitel at 800 INR a month (~$12). I can almost achieve 96 Mbps downstream and 90 upstream. No data caps. No major connectivity issues either (the connection may drop around once a month but I don't mind)