I have recently downloaded ISO file for Edubuntu but till now I have not installed it and I am using gnome now I just want to know that can I have GNOME environment in Edubuntu while installing it into my computer.
You must run
sudo apt-get install gnome-shell sudo apt-get install gnome-session
Edubuntu comes with Unity v8 (same as the newest Ubuntu releases) as its default desktop environment. However if you wanna switch to GNOME you can always do that by:
$sudo apt-get install ubuntu-desktop