The only place to get that signed is to contact the Marketing manager at the club and/or go there on match days and ask for Autographs
Leinster
... Joe Schmidt: Head Coach
Getting signed rugby balls these days by a international squad is becoming more difficult. This is because so many people as the individual Football Unions for these, signed shirts, photos etc. To get a ball you will need to contact the Irish Rugby Football Union in writing directly and address it to the Marketing Department. You can ring them however, it is not guaranteed you will speak to someone who can actually facilitate getting you a ball
You will need to be part of the squad or part of the development process through their academy
Either ebay or contact Leinster marketing team direct and they may have stock still on shelves. However, this is rare to hold old stock
You use a rugby ball to play rugby. It is shaped like an egg.
dodge ball hahaha
You must give the ball to the opposing team.
Because there is no Northern Irish team. The Ireland rugby team represents north and south, At European level there are 4 Irish teams: Ulster (which is the 6 counties of northern Ireland +3 other), Leinster, Connaught and Munster.
In Rugby, Ireland would be the better team. Ulster has some good players, but their best are brought together with the best of players from the other three provinces, Munster, Connacht and Leinster, to form a national team.
If the other team makes a mistake such as forward pass, knock-on or they kicked the ball away in rugby league the opposing team gains possession of the ball. It is the same in the union code but there are rucks, mauls, line-outs and scrums which can give the defending team opportunities to gain possession.
Soccer is where a team will kick a ball to get it into the goal at the end of the feild. Rugby is like football but without any pads.