Different udev versions has different path for rules installation. Especialy after udev was merged with systemd. But this path can be deduced from udev.pc

For example depending on udev version values could be
/etc/udev/rules.d -> usualy old udev versions

/lib/udev/rules.d -> recent versions (>=199)

and

/usr/lib/udev/rules.d > some versions in meantime (18x - 197)