The IRFU says it is in contact with the Irish Government regarding Six Nations crowd capacity but is planning for a “normal” tournament.
A limit of 5,000 spectators is in place for outdoor events in the Republic of Ireland until the end of January.
Ireland host Wales on 5 February before further home games against Italy and Scotland on 27 February and 19 March.
“For now, we are proceeding with our normal planning,” said the IRFU in a statement on Wednesday’s evening.
“We will remain in contact with government and issue updates as and when more information is available.”
The IRFU added that failure to continue planning for full crowd games “would impact ticket distribution” for the tournament.
The Aviva Stadium was able to have full capacity for Ireland’s autumn internationals in November which included the win over New Zealand which had an attendance of 51,000.