The jack must be bowled at least 19 metres for it to count as a mark.
There still seems to be some confusion about the rule for short marks.
The Laws are very clear: Only an opponent can object and call for long tapes and they must wait until after the leader has bowled their first wood.
So if you have bowled the jack and you think it is short, there is nothing you can do. You must bowl your first wood and wait to see if your opponent objects. Note: the opponent does not have to call for long tapes.
The only way you can get the jack back to try again is if your opponent objects before you have bowled your first wood or before your first wood has come to a stop.
Reference From the Laws Of The Game
4.4.a Objection to a mark set by the leader can only be made by the leader’s opponent after the first bowl has come to rest. If the opponent objects before the leader’s first bowl has come to rest, the leader may have the jack, and bowl if played, returned to have another attempt at setting a mark. Only the opponent can object to the mark. An opponent objecting to a mark must make a clear indication that an objection has been made.