/usr/i686-linux-gnu/lib64/libnss_nisplus.so is in libc6-dev-amd64-i386-cross 2.27-3ubuntu1cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/i686-linux-gnu/lib64/libnss_nisplus.so.2
/usr/i686-linux-gnu/lib64/libnss_nisplus.so.2