Campbell's Holdings Private Limited · Tiagon Holdings Private Limited · Campbell's Minerals Company Private Limited · U15541 Wb1946 Ptc013953 · Neo Carbons Pvt Ltd · Brahmaputra Carbon Limited · Guwahati Carbon Limited · Utkal Calciners Ltd · Bharat Hydro Carbons Pvt Ltd · Vedic Petrochemical Private Limited · Paradip Calciner Limited · Vedic Ferro Alloys Private Limited · Digboi Carbon Private Limited