Most registrars allow a grace period for registrants to renew expired domains. That grace period can be as short as one to two weeks or as long as one year in some cases. If the current registrant does not renew it within the allotted time frame, then that domain may become available after any grace and redemption periods during which the registrar and registry may hold the domain. The actual grace period is different for each individual registrar. Once the domain becomes available, you can register it through us.
In many cases, soon-to-be-expired domains are auctioned. If the current registrant fails to renew the registration within the allotted grace and subsequent redemption periods, you can attempt to acquire the domain by placing a bid for it.