$ sudo apt-get update
$ sudo apt-get install inetutils-telnet 

inetutils-telnet is installed in your system.

Make ensure the inetutils-telnet package were installed using the commands given below,

$ sudo dpkg-query -l | grep inetutils-telnet *

You will get with inetutils-telnet package name, version, architecture and description in a table

inetutils-telnet package basic information: