GRO online birth records have a 100 year cutoff, so just miss 1924, most of the Catholic records on the NLI website cut off in the 1880s. A search in the GRO research room is the only option, or talking to them about doing a search for you. note - the research room is due to be closed for a week or two, see Irish Genealoy News
p.s. there's an index to births for ROI on FamilySearch that covers births for 1924, up to 1958 I think, it's just an index so no parents details but includes details you need to order a cert. If the birth was registered in Northern Ireland after 1921 then check GRONI, their online system has a similar 100 year cutoff.