Hi Hirak,
Could you double check the following:
- Port, IP address and app id.
- Delete all existing registrations and register again.
- If you are connecting the device from internet make sure you have opened the required ports, you could test the ports here: http://www.yougetsignal.com/tools/open-ports/
To get more information on the issue, as Vincent mentioned you need to enable debugging for the registration component as given below:
Then do a registration from the mobile app, and look for the "Log File".
Regards, Midhun
SAP Technology RIG