3 output MOSFET? does such thing exists?
This is exceedingly driven by what you need to do, control-wise. If you just need to drive 30, one MOSFET and enough voltage will get you there - perhaps 3 MOSFETs since you mention in a comment that they are RGB. Stack them all in series, drive the desired current at the required voltage, done.

If you need to drive each of 30 RGB individually, then you're looking at 90 outputs you need to control.

Quick look with still having no real data on your parts/needs, something like SLA5085 &amp; SLA5086 seems to combine power and 5 individually controllable FETs in a package (common Source) - but you'll still need 18 of them to drive RGB.