Akash,
For the first part, going to this URL will not work:
http://10.254.169.176:8181/pc
Go to the other URL instead:
http://10.254.169.176:8181/
Now regarding the 500 server error, are the Performance Center processes running?
mysql
caperfcenter_eventmanager
caperfcenter_sso
caperfcenter_devicemanager
caperfcenter_console
If they are all running, restart the console as it may of finished starting before the Device Manager:
RHEL6:
service caperfcenter_console restart
RHEL7:
systemctl restart caperfcenter_console
Troy