Data Mining is a multidisciplinary field that focuses on data analysis and understanding. It is the process of analyzing data from different perspectives and summarizing it into useful information such as patterns, classification, clustering or segmentation, etc. that used for prediction and decision making purpose. To analyze the market situation of business organizations like ETC, having customer data is vital, in this regard the telecom companies generate and stores a tremendous amount of data such as call detail data, network data and customer data. Such data has to be systematically classified and clustered based on certain parameters to study customer behavior which in turn helps to improve service provisioning, to plan strategically future requirements that results in customer satisfaction and maximize company s revenue.