Oracle Instant Client 12.2 for macOS can now be downloaded for free from OTN.
This release is for 64 bit only. It supports:
Install instructions are at the end of the download page.
Instant Client contains libraries and tools allowing applications to connect to a local or remote Oracle Database for development and production deployment.
And if you haven't caught up with the news, Instant Client 12.2 now includes tools like SQL*Loader and Data Pump.