The last two criteria seem to contradict themselves. Is it 2500 or 2000 flying hours?
Expanding on what calmcavok has already posted....
gl69, they are two separate criteria altogether. I don't mean to point out the obvious but the "OR" in the description should have clarified this.
The criteria are 4000 total time of which 2000 must be on a multi-engine jet.
OR 2500 on a multi-engine jet.
So in other words, a Ryanair (or any other Airline which only operate Jet Aicraft), those pilots will likely reach 2500 on a multi-jet but may only have 2700 hours total time. (I'm talking about those that have undertaken a zero to hero course with minimal previous flying experience).
But on the other hand, take someone who has lots of experience, say 2000 hours on a turbo-prop aircraft, but then has recently moved onto a jet....they need 4000 hours total time, to also include 2000 hours on a multi engine jet as part of the 4000 total.
Having said that, in the past when they needed lots of pilots, you could be hired by them with less than the requirements, but could only join once you had the hours mentioned above. Not any more that I am aware of.