Install tcl8.6 by entering the following commands in the terminal:
sudo apt update sudo apt install tcl8.6
Description:
Tcl (the Tool Command Language) v8.6 - shell
Tcl is a powerful, easy to use, embeddable, cross-platform interpreted scripting language. This package contains the Tcl shell which you need to run Tcl scripts. This version includes thread support.
Homepage: http://www.tcl.tk/
Version: 8.6.8+dfsg-3
Section: interpreters