/usr/share/tcltk/tk8.4/demos is in tk8.4-doc 8.4.20-7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/tcltk/tk8.4/../../doc/tk8.4-doc/demos
/usr/share/tcltk/tk8.4/../../doc/tk8.4-doc/demos