success function in the collection.fetch was not working and because of which the control was not getting into the success function eventhough the GET request to the node server was successfull and the respose was sent back to the browser.The issue was solved with the help of this link http://stackoverflow.com/questions/8617703/nodejs-and-backbones-fetch ,valid json object was not sent and writeHead was not set to application/json.now issue is solved