$ sudo apt-get update
$ sudo apt-get install freeradius-krb5 

freeradius-krb5 is installed in your system.

Make ensure the freeradius-krb5 package were installed using the commands given below,

$ sudo dpkg-query -l | grep freeradius-krb5 *

You will get with freeradius-krb5 package name, version, architecture and description in a table

freeradius-krb5 package basic information: