At present the Doordarshan is providing the DVB T2 digital siganls in the following cities only: Delhi, Mumbai, Kolkata, Chennai, Guwahati, Patna, Ranchi, Cuttack, Lucknow, Jallandhar, Raipur, Indore, Aurangabad, Bhopal, Bengaluru and Ahmedabad.
So if you are residing within the radius of these above cities then you can enjoy the digital terrestrial services. The signals can be received by indoor antenna incase you are residing within the radius of doordarshan transmitter. But for remote areas there is least possibility to get signals. For more details you can directly contact via emails to your regional doordarshn kendra.
Terrestrial Transmission is different from DTH. Terrestrial Transmission is not privatised in India hence only Doordarshan or Prasar Bharti can provide this service.