/usr/lib/x86_64-linux-gnu/libOIS.so is in libois-dev 1.3.0+dfsg0-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libOIS-1.3.0.so
/usr/lib/x86_64-linux-gnu/libOIS-1.3.0.so