This post shows how to convert rpm packages to .deb.
As it comes from the name “terminal command” or “console command” should be executed in Terminal: open Gnome Terminal in your Ubuntu menu to go on.
Convert .rpm packages to .deb equivalents
Both .rpm and .deb files are binary packages containing pre-compiled software and all necessary components including configuration files etc. RPMs are supported by Redhat, Fedora, Centos, Suse and other Linux distributions while DEBs are for Ubuntu, Debian and related distros. Sometimes it happens that you found certain .rpm but not .deb so it looks like a problem you cannon install this package on your Ubuntu. Thankfully there is smart utility named alien that can convert .rpm to .deb. This approach is not a panacea but usually helps to install application packaged into .rpm on Ubuntu. Install it using aptitude:
sudo aptitude install alien
Convert .rpm package into .deb:
sudo alien --to-deb somepackage.rpm
Once finished you will get somepackage.deb package ready for installation via dpkg or Gdebi.
As an alternative way you can install rpm command and try installing .rpm package in your Ubuntu without converting them to .deb:
sudo aptitude install rpm