Municipal Corporation Of Delhi — installation of an extra overhead water tank

Address: New Delhi, Delhi, 110034

We are two families living in a duplex flat (Ground and first floor). We want a separate water tank (500 litres) but the top floor owner is not allowing us to install one. If there is a provision that will allow us to install one please let us know. He asked us to install a 1000 litres tank in place of the original tank obviously by removing it but we want a separate tank since we are two families with 8 members in total. It becomes very difficult to manage with one tank and distribution of water is quite uneven that way.