Ubuntu font package fonts-smc-gayathri
You can install these fonts by opening a terminal and executing
sudo apt-get install "fonts-smc-gayathri"
See also: installing software on Ubuntu, installing software on debian, and general fonts-smc-gayathri package information.
Gayathri-BoldGayathri font family with style Normal
Gayathri-RegularGayathri font family with style Normal
Gayathri-ThinGayathri font family with style Normal