Recently 19th railway zone was added in 2019. South Coast Railway (SCoR) zone covers , Guntakal, Guntur, Vijayawada, and Visakhapatnam in Andhra Pradesh
Currently operational zone:
1.Central Railways (CR):-Mumbai
2. Eastern Railways (ER:- Kolkata
3. East Central Railways (ECR:- Hajipur (Bihar)
4. East Coast Railways (ECoR):- Bhubaneswar
5.. Northern Railways (NR):- Delhi
Cover States likes Punjab, Haryana, Jammu and Kashmir, Himachal Pradesh and Union Terrritories like Delhi and Chandigarh
6. North Central Railways (NCR) :-Prayagraj or Allahabad
7. North Eastern Railways (NE):- Gorakhpur
8. North East Frontier Railways (NFR):- Guwahati
Covers Total 7 North Eastern States and few places of West Bengal like Darjeeling, New Jalpaiguri, Siliguri and Katihar in Bihar
9. North Western Railways (NWR):- Jaipur
10. Southern Railways (SR) :- Chennai
Cover States like Kerala, Tamilnadu and Union Terrritory Pondicherry
11. South Central Railway (SCR):- Secunderabad
Cover States likes Telangana and Andhra Pradesh
12. South Eastern Railways (SER):- Kolkata
13. South East Central Railway (SECR):- Bilaspur
14. South Western Railway (SWR):- Hubli (Karnataka)
This zone covers Karnataka and small Portion of Andhra Pradesh, Kuppam Town (Bangalore-Jolarpettai line and Tamilnadu state from Hosur to Semmandappatti before Salem. A.K.A Bangalore -Salem Line via Hosur
15. Western Railways (WR):- Churchgate (Mumbai)
Covers Maharashtra And Gujarat
16.West Central Railways( (WCR):- Jabalpur
17. Konkan Railways (KRCL):- Navi Mumbai
18, Metro Railway (MR), Kolkata
19. South Coast Railways (SCoR):-Visakhapatnam
Konkan Railway is not an administrative zone in Indian Railways, but rather a separate subsidiary company named Konkan Railway Corporation Limited (KRCL),
operates independent entity under the ministry of railways, managing around 741 km coastal route covering from Maharashtra (Roha), Goa (Madgaon) and Karnataka (Mangalore)
Kolkata Metro is a part of Indian Railways from 2010, because it was funded and constructed by Ministry of Railways as India's First rapid Transit system, from Beginning 1970s,
It is entirely owned and operated by Central Govt rather than Joint venture between Central and State Government.
In India, Largest Railway zone is The Northern Railway by route length, spanning approximately 6,968 km.