Take note of this path. You will need it for PATH and TNS_ADMIN environment variables.
To download and install the Oracle 12c Database Client (64-bit) for Windows, you must choose between the Full Client (requires an installer) and the Instant Client (portable, lightweight) 1. Download Options Full Database Client oracle 12c database client download for windows 64-bit
Oracle does not provide permanent direct HTTP links for 12c clients. The only official source is the Software Delivery Cloud or Oracle Support (My Oracle Support) patch download area for paying customers. Take note of this path