^^ Actually for airtel too, you need to have a landline....
For me, this is how it went:
500/- towards installation etc. is what I paid for getting the connection....
And now I need to pay 500/- pm for a 256 kbps connection (unltd till Nov, 1 GB cap after that)
The voice connection comes free and you need to pay for whatever phone calls you make on top of this 500/-...In other words, the phone doesn't carry any rental.....
However, if you are renting a modem from airtel, that's nother 99/- pm
As for the formalities, I called em up and they sent a sales rep to get the form filled...they needed 1 prrof of address (I gave my bank statement)...and a check for 500/-
next day, they installed it....