The latest Quarterly Full Stack patch was released in April for Exadata. This patch contains all of the latest recommended patches for the Exadata Database Machine.
For more details, refer to My Oracle Support Note titled Database Machine and Exadata Storage Server 11g Release 2 (11.2) Supported Versions [888828.1].
Note that the information in the note contains details for both Exadata Storage Server Software 11.2 and the new 12.1 release. This note is maintained on a regular basis so bookmark it and use it as reference for the latest Exadata Database Machine patching recommendations.