The incident raised new doubts about the future of the fragile ceasefire deal, which has paused over 15 months of war.
The six to be released on Saturday are the last living hostages to be freed under the first phase of the ceasefire in Gaza.
The sides have carried out five swaps since the ceasefire went into effect last month, freeing 21 hostages and over 730 prisoners.
Hamas released seven of the hostages in front of the destroyed home of its slain leader, Yahya Sinwar, as thousands pressed in.
The expected release will keep up the momentum of the fragile ceasefire between Israel and Hamas.
The Hamas militant group has published the names of four hostages it says it will release on Saturday as part of the ceasefire in the Gaza Strip.
Israel’s Cabinet has approved a deal for a ceasefire in Gaza and the release of dozens of hostages that will pause the 15-month war with Hamas.
Some 80% of Gaza’s population of 2.3 million Palestinians have fled their homes, many of them multiple times.