Capacity planning of 3G network unlike 2G is cumbersome. The 3G capacity is multi-fold. It depends on Power Utilization, Code Utilization, Iub (interface between the Radio Network Controller (RNC) and the Node B) and Channel Element (CE). The location of Node B plays a crucial role in 3G Planning. The Radio Frequency planner needs to select the best optimal location for setting up the 3G site in order to a seamless coverage to the customers. In this paper, these topics are explored in a detail manner. For this planning the Node B layout for Airtel in the densely populated Santhome area of Chennai is discussed. The basis issue is the interdependence between coverage and capacity in 3G. In 3G systems, both capacity and quality should be monitored to ensure the best network performance. Planning of new base station has been first treated with an analytical study of the cell coverage range for a specific environment and service. The accomplished results have been checked using ASSET simulation tool and Geographical Information System (GIS) tool.