When you install 12c Cloud Control (you can find how to install 12c Cloud Control in my previous post) it comes with its default agent which depends on your environment. If you install it on a Linux 64-bit box, you get only Linux x86-64 agent. Therefore you need to get agents for multi-OS environment which requires 4 easy steps:

1. Log on to Enterprise manager as sysman or an administrator user, from Setup menu on the right corner move to My Oracle Support --> Set Credentials to access Oracle Support.

2. Check for updates to download from Setup --> Extensibility --> Self Update

A job will be created to check, you can schedule it for later or run it right away. 

3. When job succeeded, go to Setup --> Extensibility --> Self Update. Dig into Agent Software, select the ones you want to download and click download.

Again a job will be created.

4. When download job succeeds, go back to Agent Software page, select the one downloaded and apply it.

Now agent software is ready to deploy.