The PS5000 is a 16-disk system. It looks like you have 2TB drives (~1.82 TiB) based on the numbers you provided.
Dell's documentation on choosing RAID policy states that according to "best practices", RAID50 should not be used for 7.2K disks larger than 1TB, and RAID5 avoided completely, when storing business-critical data.
A single "member" (enclosure) can only be configured with one RAID policy, and cannot be split into 2 separate levels. Implementing multiple RAID types is accomplished on EQL systems via multiple members/arrays stored in separate "pools".
RAID10 would be my suggestion for database workload, but that may not provide adequate usable capacity depending on the size of your VMs.
If the virtualization and database workload/size already "exist" on some other storage, it may be wise to look into some numbers there (e.g. read/write ratio, average and "peak" IOPS, total capacity/size, etc).
RAID6 provides miserable performance for write-intensive workloads, so I'd suggest avoiding it unless the vast majority of your IO is made up of reads. That number of drives in RAID6 could theoretically sustain 1500 IOPS with 100% reads (with one hot spare, 8K random IO), but 30% writes cuts that to below 600.