Hi Rajesh,
Make sure that you are not trying to reach a server with a different host name, odata services in portal must have the same host name exactly (use web dispatcher or reverse proxy) and also that the protocol is the same for both e.g http or https.
now try to run it again and open the developer tools (f12) go to network tab and search for the URL you entered, if it's not there then the browser blocked it --> look in console for errors.
If it is there look at the response --> what is the status? 200? 404? etc.
If it's 200 make sure that the returned data is either a json or just a number.
If you can show the details from the network tab it will help.
BR,
Saar