Bihar Carbons Private Limited · Brahmaputra Carbon Limited · Digboi Carbon Private Limited · Neo Zinc Oxide Private Limited · Vedic Ferro Alloys Private Limited · Campbell's Holdings Private Limited · Guwahati Carbon Limited · Tiagon Holdings Private Limited · Campbell's Minerals Company Private Limited · Neo Carbons Pvt Ltd · Paradip Calciner Limited · Vedic Petrochemical Private Limited · Shree Hanuman Oil Mills Ltd