I don't know what you are trying to ask.
If your joomla update doesn't work.. how possible this can be related to our template? this is 101% related to your server, apparently the cURL doesn't work in your server. Or Joomla didn't release or stop releasing the automatic upgrade package from joomla2.5.11 to joomla2.5.16.
browse
www.joomla.org and download the;
Joomla2.5.xx to Joomla 2.5.16 upgrade package and update your joomla manually by installing the package through "Joomla Extension Manager"
Case solved. Topic is closed.