parallel charging on three powerlab 8

[meangenesracing]

Can I parallel charge 2 6s 5000 mah and 2 5500 mah 6s together at the same time thanks in advance for any and all help

[meangenesracing]

Sorry not three I meant the, this stupid phone lol

[785boats]

Yes the charger won't have a problem with that. But your power supply needs to be rated to at least 25A at 24V or 45A at 12V to give you the 500+ watts you will be drawing for a 1C charge on all 4 batteries.
Different capacities or C ratings aren't a problem when parallel charging if that was your main concern. Just make sure the packs are close in cell voltage first & plug all the main power leads in and let the voltages equalise for a couple of minutes BEFORE you plug in any balance leads.

I'm a great fan of parallel charging but I only ever do two big 6s packs at a time myself. On my Hyperion Duo charger I can do two packs on each channel at the same time, giving a total of 4.

[meangenesracing]

This charger does have a storage charge mode correct?

[785boats]

Yep. Page 74 of your manual.