Raghav,

Raghav Gururajan wrote:
> I tried installing the package "Transmission". It is not showing 
> up in
> GNOME Menu.

Transmission's GTK GUI interface is in a separate package output 
(to keep the main output from depending on GTK+, which is quite 
huge).  Install ‘transmission:gui’ and you'll be happy.

The :gui output also provides a .desktop file that should make 
things like GNOME add it to their launcher.

> Typing "transmission" on terminal also not starting the
> application.

The command is ‘transmission-gtk’; ‘transmission’ doesn't exist.

Kind regards,

T G-R