Step 1: Railway zones in India.
- Bilaspur is the headquarters of South East Central Railway.
- Hajipur is the headquarters of East Central Railway.
- Kolkata is the headquarters of Eastern and South Eastern Railways.
- Indore is not the headquarters of any railway zone.
Step 2: Analyzing the options.
(A) Bilaspur: Correct HQ of SECR.
(B) Hajipur: Correct HQ of ECR.
(C) Indore: Correct answer — not a railway zone HQ.
(D) Kolkata: HQ of Eastern Railway.
Step 3: Conclusion.
Thus, Indore is not a railway zone headquarters.