/usr/lib/x86_64-linux-gnu/libitcl3.4.so is in itcl3-dev 3.4.3-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libitcl3.4.so.1
/usr/lib/x86_64-linux-gnu/libitcl3.4.so.1