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.
Israel overnight said it had received a list of information on the status of the hostages from 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.
Hamas triggered the war with its Oct. 7, 2023, cross-border attack, which killed some 1,200 Israelis and took 250 others hostage.
Officials say Hamas has accepted a draft agreement for a ceasefire in the Gaza Strip and the release of dozens of hostages.
One of the three officials and a Hamas official said that there were still a number of hurdles to clear.