Need suggestions for rainwater harvesting in a clay soil water table around 5 to 6 feet depth in an apartment in Velachery, Chennai, TN

Hello,

        I am one of the resident of 156 flats apartment complex at Velachery, Chennai. The rain water absorption is slow because of clay soil and also the salinity of water is very high. Further water table level is just about 5 to 6 feet. below ground level. What would be the best suggestion towards rainwater harvesting for the above conditions.

Thanks for assistance.

regards,

Guha