Hi,
PRSI applies to the year prior to the current year, so if I'm right, you are now looking at claiming based on 2009 PRSI. Were you a PAYE worker in 2009 and made at least 49 (I think) weeks PRSI contributions?
If not, you won't be eligible for any PRSI benefits including Jobseekers Benefit.
However you will be eligible for the standard Jobseekers Assistance.
As this is means-tested, you must apply for the Assistance and then wait for an officer to perform the means test.
So in the meantime, immediately after you apply for Assistance, you take yourself down to the local Community Welfare Officer and apply for Supplementary Welfare Allowance. The CWO's tend to have established times when they accept applications, so find out which one you need to go to, and find out when he is open.
The SWA will be equal to what you will probably get from the Jobseekers Allowance.
If you are renting, you should also apply for the Rent Allowance.
The CWO also help out with things like buying prams, funding baptisms, etc. etc. Which explains why all the people in the council flats across the way from me have more expensive prams for their infants than I do.