CIL produces coal through seven of its wholly owned subsidiaries. These are Eastern Coalfields Limited (ECL), Bharat Coking Coal Limited (BCCL), Central Coalfields Limited (CCL), Western Coalfields Limited (WCL), South Eastern Coalfields Limited (SECL), Northern Coalfield Limited (NCL), and Mahanadi Coalfields Limited (MCL).
CIL's seven subsidiaries are responsible for coal production. These include: Eastern Coalfields Limited (ECL), Bharat Coking Coal Limited (BCCL), Central Coalfields Limited (CCL), Western Coalfields Limited (WCL), South Eastern Coalfields Limited (SECL), Northern Coalfield Limited (NCL), and Mahanadi Coalfields Limited (MCL).