The Provisional IRA which were the main actors throughout the troubles formed by the larger unifying groups that split off from the Leninists and Marxists and were mostly Catholic Nationalists
You don't even know enough to make the distinction from The Official IRA. So why talk?
I can tell you there is nothing conservative about the IRA. They were violent marxist who hated the British. While they were from mainly catholic areas, they were not practicing catholics.