I think the unpalatable reality is that you are now looking for 'any' school rather than a 'good'/popular school. As mentioned above, most/all 'good'/popular schools will have their places filled for September this year and, in fairness, can't be expected to keep a few places for possible newcomers if they have actual applicants on a waiting list - and things are particularly bad now because of the baby boom in the late 1990s/early 2000s. If fee-paying is not an option, you should probably just apply to every school in areas that you would consider living - then if any of them have spaces (and I expect some will), ask here or on rollercoaster.ie for peoples' views on which is best/least worst. It's not a great selection process but it is probably what needs to be done. The Department of Education has a school-finder at
http://www.education.ie/en/find-a-school which will help you find all the schools in each area. Good luck!