Based on the information supplied by the Deputy, it is not possible to definitively state the type of application that should be made. However, it would appear that an application for a de facto partner of an Irish National may be the most appropriate application. Further details on how to make such an application are available on my Department's website at: www.irishimmigration.ie/coming-to-join-family-in-ireland/ and at:
www.irishimmigration.ie/coming-to-join-family-in-ireland/joining-an-irish-national/de-facto-partner-of-an-irish-national/
It is open to anyone to create a visa or preclearance application at any time to suit their particular circumstances. Visa applications must be made on-line at: www.visas.inis.gov.ie/avats/OnlineHome2.aspx
Upon creating an on-line visa application, the summary sheet must be printed and signed by the applicant and then submitted to the relevant Visa Office, along with supporting documentation and the relevant fee, within 30 days. Upon receipt of this, the visa application will be processed.
If the applicant intends to enter the State with a view to residing here for more than 90 days, they should apply for a D Type - Join Family visa application. If they intends to visit for less than 90 days, they should apply for a C Type - Visit Visa.
In all cases, the onus is on the applicant to satisfy the Visa Officer that a visa should be granted.