To verify the version of Java that SITEOPS is using, open SITEOPS and click Help => About SITEOPS.

Locate the Operating System line. If you see amd64 then SITEOPS is using 64-bit Java. If you see x86 then SITEOPS is using 32-bit Java.

You can download the offline 64-bit version here: http://www.java.com/en/download/manual.jsp