Improvement Of Stormwater Drainage Capacity By Providing 400 Mm And 500 Mm Diameter Np3 Rcc Ss Pipes Including Appurtenance Structures And Ancillary Works Within Zone-3 And 4 Of Calcutta Leather Complex On Turnkey Basis Under Sector-Vi Ita Sec-Vi/Ita/12 Of 2025-2026 Sl-03