If he gets a job, he will then get paid class A Prsi contributions. If he later ceases to be employed, he should then sign on for class A credits.
It is a good idea to remain in the class A Prsi system. It would allow him to qualify for Treatment Benefits and help towards qualification for 65s benefit, if he doesn't intend working after age 65.
If he can manage to get 260 paid class A contributions he will qualify for a pro rata pension.
Get him to check his Prsi contributions record. He probably has a few years of reckonable Prsi contributions pre establishment.