This process of activating do not disturb service is all same for Aircel, Airtel, BSNL, Tata DoCoMo, Idea Cellular, Loop Mobile, MTNL, Reliance Communications, MTS India, Tata Indicom, Uninor, Vodafone and etc.
Fully Blocked Category
Send SMS at START 0 to 1909 or Call at 1909
Partial Blocked Category
Send SMS at START 1 to 1909 to block Banking – Insurance – Financial Products – Credit Cards
Send SMS at START 2 to 1909 to block Real Estate
Send SMS at START 3 to 1909 to block Education
Send SMS at START 4 to 1909 to block Health
Send SMS at START 5 to 1909 to block Consumer Goods & Automobiles
Send SMS at START 6 to 1909 to block Communication – Broadcasting – Entertainment – IT
Send SMS at START 7 to 1909 to block Tourism
You can also De-Register the DND service to receive the marketing calls and messages in future. To do that, just send an SMS STOP and send it to 1909. You can also call 1909 to cancel the service.