(APN)user name=bsnlnet; password not required.
No authorization required if possible disable authorization.
In some Mobile phone ask APN as Account name and User name as APN.
For past 3 days I was not able to send SMS from my new BSNL SIM. But the package offers 1000MB GRPS usage when I contacted my customer care in person I found this to be working and SMS problem cleared.
Moral: Always approch BSNL customer care in person!
This dose not mean you need not pay one ordinary login cost 0.2INR.