/usr/lib/x86_64-linux-gnu/libnetcdff.so.6 is in libnetcdff6 4.4.4+ds-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libnetcdff.so.6.1.1
/usr/lib/x86_64-linux-gnu/libnetcdff.so.6.1.1