Here's the main downloads page:

http://www.oracle.com/technetwork/database/enterprise-edition/downloads/index.html

If you click on see all next to Microsoft Windows (x64), it'll take you to this page:

http://www.oracle.com/technetwork/database/enterprise-edition/downloads/112010-win64soft-094461.html

The second section contains the Client download (win64_11gR2_client.zip).

If you want the ODAC 64 drivers for an old version of the client, then they are found here:

http://www.oracle.com/technetwork/developer-tools/visual-studio/downloads/index.html