| | Airport Authority of India | |
| | | Kolkata Municipal Corporation |
Steel Authority of India Limited | Bharat Heavy Electricals Limited | National Thermal Power Corporation Limited | Damodar Valley Corporation |
| Hindustan Petroleum Corporation Ltd | | |
| | Garden Reach Shipbuilders & Engineers Limited | Defence(MES, Army, Navy & Airforce) |
| | National Aluminium Company Limited (NALCO) | Public Health Engineering Department |
Shapoorji Pallonji & Co. Ltd | Nagarjuna Construction Co. Ltd | Alstom Project India Limited | Uranium Corporation of India Limited |
Hindustan Construction Company Limited | Techno Electric & Engineering Ltd | Simplex Concrete & Piles India Ltd Project India L | Jaiprakash Industries Ltd |
| | | Bharat Sanchar Nigam Limited |
Andman Public Works Department | | | West Bengal State Electricity Board |
| | Gannon Dunkerely Company Ltd | |
Royal Government of Bhutan. | Bengal Peerless Housing Development Company Ltd. | | |
Shapoorji Pallonji & CO. Ltd. | ITD Cementation India Ltd. |