How to Block Unwanted Calls in All Mobiles

In india there are more than 50 crores of mobile customers and now a days the number of telemarketing calls you receive everyday is keeping on increasing and people are frustrated when they receive a call.n india there are more than 50 crores of mobile customers and now a days the number of telemarketing calls you receive everyday is keeping on increasing and people are frustrated when they receive a call.
 
registration in NDNC Registry by clicking on "DND Registration Check"
http://ndncregistry.gov.in/ndncregistry/index.jsp
 
Stop unwanted calls in Airtel:
Airtel postpaid and prepaid mobile users sms “START DND� to 121 and broadband and landline customers call 121.

Stop Unwanted Calls on Vodafone:
You need to send a SMS ACT DND to 111

Block calls from reliance:
http://www.reliancecommunications.co.in/Communications/Rm/rm_index.html and fill up a form to register to dnd.

Stop Calls on Idea Callular -
Call up 1909 to register to DND.
or SMS "START DND" to 1909 and for un-listing / de-activating DND send "STOP DND" to 1909.

Tata Indicom:
http://www.tatatele.in/dnd/DNDAction.do use this link to activate DND.

Tata Docomo:
If you want to register yourself on the NDNC registry, simply SMS START DND to 1909 (toll free) and in case you want to de-register yourself from the NDNC registry SMS STOP DND to 1909 (toll free).

BSNL:
http://pdnc.bsnl.co.in/
Interactive Voice Response System (IVRS) â€" Call Toll-free number 1909 and follow the IVRS instructions for registring/de-registering.
SMS  Send SMS to 1909 with keywords ‘START DND’. It will be registered. For de-registering SMS ‘STOP DND’ and it will be dergistered.