The first industrial undertaking where CISF was inducted was

The first industrial undertaking where CISF was inducted was

HEC, Ranchi.
RCFL, Mumbai.
BCCL, Dhanbad.
Rourkela Steel Plant.
This question was previously asked in
UPSC CISF-AC-EXE – 2021
The Central Industrial Security Force (CISF) was established in 1969. The first industrial undertaking where CISF personnel were deployed was the Fertilizer Corporation of India (FCI) plant located in Trombay, Mumbai. Rashtriya Chemicals & Fertilizers Ltd. (RCFL) is the successor entity to this unit of FCI. Therefore, RCFL, Mumbai, represents the first industrial undertaking where CISF was inducted among the given options.
CISF was created to provide integrated security cover to public sector undertakings (PSUs) across India.
Other early deployments included Heavy Engineering Corporation (HEC) Ranchi, Rourkela Steel Plant, and various coal mines under entities like BCCL, but the FCI Trombay unit (now part of RCFL) was the first.