The Republic have risen eight places to 26th, whilst rivals Northern Ireland have dropped to 23rd, but neither side will be seeded for the draw which will take place in Zurich at 14:00 CET tomorrow.
Northern Ireland miss out after losing their last two qualifiers against Germany and Norway, allowing Denmark to leapfrog them in the rankings.
The pair will face one of seeded quartet; Italy, Croatia, Denmark or Switzerland, whilst Greece and Sweden are the final two unseeded sides.
The eight teams invovled are ranked as follows: Switzerland (11th), Italy (15th), Croatia (18th), Denmark (19th), Northern Ireland (23rd), Sweden (25th), Republic of Ireland (26th) and Greece (47th).
The seeded sides will be placed in Pot one for the draw and the unseeded side in Pot two.
Unlike in other draws, the seeded side will not necessarily have the advantage of playing the second leg at home.
One ball will be taken from random from each pot and placed into a third pot, with the first team to be drawn from this third pot playing the first leg at home.
The first legs will take place between 9 and 11 November and the second legs between 12 and 14 November. In the event of a draw, away goals will be taken into account.
If even away goals cannot separate the sides after the second leg, extra-time will be played with the away goals rule still in effect. To halves of 15 minutes will be played, with a penalty shootout to follow if the scores remain level.
Mexican TV presenter Vanessa Huppenkothen and former Spanish international Fernando Hierro, who played in three World Cups, will conduct the draw.