.rpm to .deb and .deb not installed code example
Example 1: install deb file
sudo dpkg -i /path/to/deb/file
sudo apt-get install -f
Example 2: how to install .deb file ubuntu
sudo dpkg -i package_file.deb
sudo dpkg -i /path/to/deb/file
sudo apt-get install -f
sudo dpkg -i package_file.deb