Not able to find DVD which is already inserted in pc. Kindly suggest the location where we will detect it.
Version : ubuntu 16.04
There are some things to check...
Have you installed
udftools? If not ...
sudo apt install udftools
udftools is a tool for UDF filesystems (= cd and dvd).
eject -n This should show you the device.
eject -tshould eject your DVD.
sudo hwinfo --cdromshould show you info about the DVD.
Please edit results into your question. Since this is partly a comment ... Ill remove it if it has not got a working method.