User Experience...

My experiance is

i) If you have bsnl, go with dataone
ii) If you have patience and your area is feasible go with tata indicom
iii) If bharathi is available, take broadband and phone
iv) Better go to surfing center than paying sify. You can see the hell
on earth after getting sify connection

All broadband connections come with no support. Useless help desk.
All companies wanted to get more money with leased lines. I heard
bharathi is better. Bharathi concentrate only in certain areas, which is
also bad.

Source: India Broadband Forum