The basic rule about placing the circle is in Article 7 – the circle is drawn or placed (a) on the assigned terrain (b) around the place X on the assigned terrain where the jack was sitting at the end of the previous mene.
Traditionally, if the jack is sitting on the terrain in location X and then hit and knocked out of the terrain, at the beginning of the next mene the circle is placed around location X, even if X was not marked. Approximately is good enough. This rule is perfectly suited to playing in the traditional way, on an unmarked terrain. You can find the rule in Article 12.
Umpires generally proceed on the rule that nothing can be placed, or put back, in a location that wasn’t marked. They are also used to umpiring only games played on marked terrains, where it is relatively easy to see and remember the place where a hit jack crossed a boundary string. Umpires have therefore invented an alternate (unwritten) rule to replace the traditional practice. The rule is—
If during the previous mene the jack was knocked out of the assigned terrain, the circle is placed on the assigned terrain as close as possible to the last place that the jack was still alive.
This means that if the jack ended up dead because it went out-of-bounds, the circle is placed on the assigned terrain as close as possible to the place that the jack crossed the dead-ball line. If the jack ended up alive on a neighboring terrain, then the circle is placed on the assigned terrain as close as possible to the jack’s final location on the neighboring terrain. In umpired play, this is how an umpire will rule.
Note that there are ways that the jack can die without ever leaving the assigned terrain.
- It can end up floating in a puddle of water.
- It can be hidden from view by a feature of the terrain.
- It can be hit to a location on the far side of a patch of dead ground.
- It can be hit and come to rest more than 20 meters, or less than 3 meters, from the circle.
In all of these cases, the jack hasn’t left the assigned terrain, so Article 7 applies. The circle is “drawn or placed around the place where [the jack] was located in the previous mene”. If, for example, the jack died because it was knocked back and came to rest 2 meters from the circle, then the circle is placed around the location where the jack came to rest—which, in this case, is only 2 meters from the circle’s previous location.
Even if the jack was on the assigned terrain when it died, other rules still apply. You still have to place the circle a meter away from any throwing obstacle. If the jack died because it ended up floating in a puddle, you don’t put the circle down in the puddle. The puddle is a throwing obstacle, so the circle is placed a meter away from the edge of the puddle. Similarly, if the jack ended up hidden under a pile of leaves, you don’t put the circle down on the pile of leaves.
 Article 12 says— “If, during a mene, the jack is displaced onto another game terrain … At the following mene the teams continue on the terrain that was assigned to them and the jack is thrown again from the place it occupied when it was displaced…” Article 12 doesn’t tell us what to do when a jack goes out-of-bounds because Article 12 was designed for play on unmarked terrains where there is no such thing as out-of-bounds.
 There is an interesting Youtube video where Pascal Milei shoots the jack out-of-bounds and you can see Marco Foyot placing the circle in the traditional way around location X. The umpire comes onto the terrain and corrects him. The umpire points Marco to the place at the foot of the lane where the jack went out-of-bounds, and shows him where to place the circle, close to the dead-ball line.
 Note that knocking the jack farther than 20 meters from the circle is usually possible only on an unmarked terrain, but theoretically it could be possible on a marked terrain if the marked terrain was large enough.