Question: we are working on uninstalling specific applications based upon application transparency report , however we only see the file evidence for those specific applications not any installer hence question is do we have to consider this file evidence ( there is no installer evidence found) as actual proof for actual installation of applications showing into report.

Yes, the presence of File Evidence indicates that something is installed on the machine.

There are many reasons why there is no installer evidence for an application. For example, many Unix-like OSes do not use a traditional installer, but have the user extract files on to the machine. The application would still be installed, usable and possibly licensable, but there would be no installer evidence record.