Stella ost to pst is the best recovery software to recover all your ost file data into a pst file. Stella's ost to-pst recovery software retrieves all ost email items in the pst folder. All ost mailboxes can be restored to the office 365 account using stella's ost to pst restoration software. This software will convert all ost mailboxes into a pst folder.
You can find more information at this link
https://www.stelladatarecovery.com/ost-to-pst-converter.html