The organisers themselves decide when and how an event goes on sale. On the details page of the event we indicate the start date and time of the on sale. If you cannot find the event on www.teleticketservice.com, this means that it is not (yet) on sale with us.
For more information, please check the website of the artist, the organiser or the venue where the event (possibly) takes place, in as far as they have already communicated about it.