I agree to what Parminder has said.
If you have any option of any Wired Broadband go for that.
But if you dont have any option like that (like me) then Tata is best.
Tata has around 150 towers in Bangalore (Reliance has around 50)
Reliance customer care is worst, they will take months to install a new connection and then forget it. You keep on calling them but you will never get any responce. I have heared that there is only one to get answer and that is to write to Ambani.

While Tata is much better here. You can imagine it from the fact that Reliance is much behind in putting hardware and Towers than Tata but still see the hype and publicity thay have made for it.

Overall, Go for Wireline connection if possible. and never go for Hathway
Otherwise if Wimax is only option then try Tata