| Central Region (CR) | Bhagalpur (3201), Muzaffarpur (3205), Patna (3206), Agra (3001), Bareilly (3005), Kanpur (3009), Lucknow (3010), Meerut (3011), Prayagraj (3003) | Bihar and Uttar Pradesh |
| Eastern Region (ER) | Port Blair (4802), Ranchi (4205), Balasore (4601), Berhampore (4602), Bhubaneshwar (4604), Cuttack (4605), Dhenkanal (4611), Rourkela (4610), Sambalpur (4609), Gangtok (4001), Kolkata (4410), Siliguri (4415), Kalyani (4419) | Andaman & Nicobar Islands, Jharkhand, Odisha, Sikkim, and West Bengal |
| Karnataka, Kerala Region (KKR) | Kavaratti (9401), Belagavi (9002), Bengaluru (9001), Hubballi (9011), Kalaburagi (9005), Mangaluru (9008), Mysuru (9009), Shivamogga (9010), Udupi (9012), Ernakulam (9213), Kannur (9202), Kollam (9210), Kottayam (9205), Kozhikode (9206), Thrissur (9212), Thiruvananthapuram (9211) | Lakshadweep, Karnataka, and Kerala |
| Madhya Pradesh Region (MPR) | Bilaspur (6202), Raipur (6204), Durg-Bhilai (6205), Bhopal (6001), Gwalior (6005), Indore (6006), Jabalpur (6007), Satna (6014), Sagar (6015), Ujjain (6016) | Chhattisgarh and Madhya Pradesh |
| North Eastern Region (NER) | Itanagar (5001), Guwahati (5105), Imphal (5501), Shillong (5401), Aizwal (5701), Kohima (5302), Agartala (5601) | Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura |
| Northern Region (NR) | Delhi (2201), Ajmer (2401), Alwar (2402), Bikaner (2404), Jaipur (2405), Jodhpur (2406), Kota (2407), Sriganganagar (2408), Udaipur (2409), Sikar (2411), Dehradun (2002), Haldwani (2003), Haridwar (2005), Roorkee (2006) | Delhi, Rajasthan, and Uttarakhand |
| North Western Region (NWR) | Chandigarh/Mohali (1601), Hamirpur (1202), Shimla (1203), Jammu (1004), Samba (1010), Srinagar (1007), Amritsar (1404), Jalandhar (1402), Ludhiana (1405), Patiala (1403) | Chandigarh, Haryana, Himachal Pradesh, Jammu and Kashmir, Ladakh, and Punjab |
| Southern Region (SR) | Hyderabad (8601), Kurnool (8003), Vijayawada (8008), Visakhapatnam (8007), Chennai (8201), Madurai (8204), Chirala (8011), Cuddapah (8013), Guntur (8001), Kakinada (8009), Nellore (8010), Rajahmundry (8004), Tirupati (8006), Vizianagaram (8012), Puducherry (8401), Coimbatore (8202), Krishnagiri (8209), Salem (8205), Tiruchirapalli (8206), Tirunelveli (8207), Vellore (8208), Karimnagar (8604), Warangal (8603) | Andhra Pradesh, Puducherry, Tamil Nadu, and Telangana |
| Western Region (WR) | Ahmedabad (7001), Aurangabad (7202), Mumbai (7204), Nagpur (7205), Nashik (7207), Pune (7208) | Dadra and Nagar Haveli, Daman and Diu, Goa, Gujarat, and Maharashtra |
