CORAS is a separate Commando Unit of the Railway Protection Force (option-3). To better understand the answer, let`s examine each option:
Option-1: National Security Guard (NSG) is a specialized counter-terrorism unit of the Indian government. CORAS is not a part of NSG.
Option-2: Central Industrial Security Force (CISF) is a central armed police force in India. CORAS is not a part of CISF.
Option-3: Railway Protection Force (RPF) is a security force tasked with protecting the Indian railway system and its passengers. CORAS is a specialized commando unit established within the RPF to provide enhanced security and counter-terrorism measures for railways.
Option-4: Central Reserve Police Force (CRPF) is a central paramilitary force in India. CORAS is not a part of CRPF.
Based on the information provided, it is clear that CORAS is a separate Commando Unit of the Railway Protection Force (option-3).