This is not correct. You are talking about a management agent/agency which is often employed by a management company (usually owned and run by the householders/property owners) to do the day to day management of an estate/development/complex.Residents Association are made of member within the block of flat or estate that you live in, however, I think there are rules that they have to adhere to and hold a certain number of meeting each year and inform other residents that the meeting is going to take place.
A management company is an outside organisation and they are normally employed by the landlord or landlady to carry out maintenances of the estates or block of flats.
Your local Councillor or Councillors may know of a resident association/group if there is one on your estate or nearby. Dublin City Council also have listings but I think they would be the bigger Resident Assocations that have been in existence for decades.