/usr/lib/x86_64-linux-gnu/libtk8.6.so.0 is in libtk8.6 8.6.6-1+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libtk8.6.so
/usr/lib/x86_64-linux-gnu/libtk8.6.so