The Job Scheduler is a 32bit engine but you can run it on every supported 64bit platform.
The Job Scheduler requires a Sun Java Runtime Environment (JRE) 32-Bit at least version 1.6.x.
For AIX you can use the IBM Java 32-Bit at least version 1.6.x, too.
You can install the 32Bit Java in parallel to a 64Bit version.
See Z-JAVA-101_Java_Virtual_Machine_is_not_started for more information.