And finally heres the official Do Not Call Registry aka National Do Not Call Registry (NDNC Registry)
*ndncregistry.gov.in/ndncregistry/index.jsp
Though it doesnt seem to be fully functional at the moment.
According to GoBroadband:
The National Do Not Call Registry of India, an initiative by TRAI is Up and Running now. TRAI in a notification in early June had promised to take the registry live in 3 months.
The registry has an issue. If you subscribe to BSNL Landline, Airtel Mobile and Vodafone-Hutch-Essar Blackberry, then you have to register yourself with all the 3 operators separately and it will take 45 days to propogate to the NDNC Registry. You can register with your Telco by an SMS or through a web based interface. Here is a list of Do Not Call / Disturb Links for you to register of Telecom/Mobile Operators and Financial Companies. [Though registration with financial companies may not be needed any more if your Phone is in the DNC list]
A Tele-marketer in India is now obligated to become a member of this registry and download the list of subscribers who have opted out of Unsolicited Commercial Communication before making any calls.