Synchronize SQL server databases
Sounds to me like Merge Replication, considering the offline aspect. You generally have a "master" which the "clients" sync to. https://docs.microsoft.com/en-us/sql/relational-databases/replication/merge/merge-replication?view=sql-server-2017
I would question the need to distribute the database in the first place. Makes things soooo much more complicated, so carefully weigh the gain you get from distributing the database to the headaches you get from it.