AIX only has support for software RAID0. For other RAID levels, you will need a RAID adapter as mjurado has mentioned.
The RAID adapter (#2498) PCI 4-Channel Ultra3 SCSI RAID Adapter has support for RAID levels 0, 1, 1E, 5 and 5E.
This adapter is not bootable. If you want to install the 2104-DU3 with hardware RAID 0, 1, 1E, 5 and 5E, the you will have to connect the DU3 to this RAID adapter. You cannot install AIX on the DU3 when running on this adapter. You will need a minimum of one disk sitting in the 610 for installation of AIX. If you want to mirror the OS, then you can use AIX mirror to perform this, which requires two disks installed in the server. AIX has support for up to three way mirror but I rather think that this is a waste of HDD space.
As for different RAID levels on the disks in the DU3 subsystem, yes you can have different RAID levels. You will have to specify different RAID groups and allocate the disks to these groups.
If I am not mistaken, this adapter requires some APARs for AIX 4.3.3. Check under IBM support for updates.
Regards.