I want to upgrade ubuntu 14.04 to 16.04LTS offline on multiple systems in my organization. i want to know how can upgrade ubuntu offline in multiple systems.Please help me to upgarde ubuntu 16.04 offline.
The easiest way is to download from the official page
the last version and install it to your devices, one-by-one.
Installation does not need internet connection. Once you download the last version, you can install offline on your machines. (But better to connect them, before or later, to update the system.)
Here's how you create a bootable USB in linux http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-ubuntu