MTNL is offering this facility through following options: 
1. IVRS

1. Subscriber can dial 1909 through his/her Telephone Number (MTNL phone or mobile) then Press 1 for Registration, 2 for Withdrawal and 3 for Complaints.
2. After the completion of request appropriate message will be played.

2. WEB Portal 

Public URL: http://203.94.244.126/nodalapps/internal/defaultcustdnd.asp

1. Subscriber can enter Mobile No / Fixed line No / Garuda number

 2. If validation is successful then following options shall be displayed

a. Registration
b. Withdrawal
c. Complaints

 3. Subscriber can select the required options, fill the fields as per instructions and submit.
 4. After validation, appropriate message shall be displayed.  

3. SMS

 For registration:
 Subscriber can send:  START DND to 1909

 For withdrawal:

 Subscriber can send:  STOP DND to 1909

For Registration/ Withdrawal no further information is required through this method as mobile Number of subscriber is treated as identification. A Docket No will be allocated to subscriber through a return message.

4. Call Center

Registration, withdrawal and complaints are also handled at the respective call center.

For CDMA: 1502, PSTN and Broadband: 1500, GSM: 1503

Note: As per TRAI guidelines DND complaints can be booked only after 45 days of DND registration and withdrawal is possible only after 90 days of DND registration.