Not sure about chennai telecom.Here if you don't have a land line you have to apply for a land line first and have to deposit Rs. 500/- alongwith the application.You are to apply for BB after you get the number for your new telephone.Your First Bill will include:1. Rs. 1000 /- as security deposit for your phone.2. Rental of B-phone since installation of B-phone to converting to combo plan.3. BB rental of First month 4. One month rental of BB as security deposit.