Oracle Full Client / Database Client package locations
When it comes to software downloads for production use, the Oracle sites, thankfully, are a little less of a maze - provided that you are familiar with the entrance.

You can find the latest media packs for production use on the Oracle Software Delivery Cloud.

After logging in and accepting terms and export restrictions, select Oracle Database and Linux x86-64. After hitting Go, you should be able to find Oracle Database 11g Release 2 (11.2.0) Media Pack for Linux x86-64 and within; the Oracle Database 11g Release 2 Client (11.2.0.1.0) for Linux x86-64.

You can find Oracle Database 12c Release 1 (12.1.0.2.0) Media Pack for Linux x86-64 and the associated Oracle Database 12c Release 1 Client (12.1.0.2.0) for Linux x86-64 (64-bit) in much the same way.

The patch from 11.2.0.1.0 to 11.2.0.2.0 should be downloaded from Metalink / My Oracle Support.

Starting with 11.2.0.2.0, any subsequent updates can be downloaded from with the installer itself, either as an integrated part of the installation process, or in advance (useful when destined server is restricted from accessing the Internet) by running the installer with the option -downloadUpdates.

I guess you have already considered just running the datapump tools from the actual Oracle home of the database in question?

These days, you may also be offered to try out a new and enhanced version of the software delivery cloud. Look for a big link on the landing page/login page.

On a final note, lots of additional information can be found in the Client Installation Guides available in the Oracle Database Online Documentation 11g Release 2 (11.2) or Oracle Database Online Documentation 12c Release 1 (12.1).