Yes, the Treasure chest game, is having prizes in one of chest out
of 9 randomly everytime you play. As already said, its completely
random. The chances or probability of getting the prize (choosing
the right chest) is 1/9. And also, the answer of your question is
also yes and also no. Partially no, because it is complete
randomness and depends on your luck. You may even not get the prize
in that box because of the randomness that the prize would be
randomly lurking around in those other 8 boxes even after you play
hundreds-of-times. And, partially yes because as the chances are
1/9 and as pick the same box again and again, the chances will
increase that prizes may come into that box too.
Anyways, its complete randomness and luck. You can choose whatever
box you want. If you are lucky, you'll have the prize even if you
choose the same box everytime.