In January 2011, the Indian Cabinet Committee for Security approved four more Kolkata destroyers to be built as Project 15B. The Project 15B vessel will retain the hull form of Kolkata class destroyers and most of its systems, there will be some significant upgrades. For example, some structural changes in the superstructure will improve stealth and include better sound and infrared suppression. The Project 15B will also differ from the Project 15A through employing a fully flush deck. This will improves stealth because of the smoothness of the overall deck with far fewer angles and corners. The displacement of each Project 15B will be approximately 7,000 tons, a 200 ton addition over the Project 15A Kolkatas.
. Project 15B will also be armed with the new Nirbhay land attack cruise missile (1,000 km range), the hypersonic Brahmos-II anti-ship cruise missile (300 km range) and an Extended Range Surface to Air Missile (ER-SAM) (100 km range).
Construction of the first Project 15B, INS Bengaluru, D66, has already started and is well underway..