uninstalling updates

[Android Question]

i have xolo a600.i updated xolo power from google play from 10.4 version to 11.6 version..now i want my old version back so i uninstall updates..but the old version didnt get reinstalled.i tried it reinstallin from manage apps in settings.it is there but it is written there NOT INSTALLED.it is a system app,so it should be installed by itself.i hae android 4.2.2..need help.

thank you