The first thing that needs to be done is to determine exactly which version of Office 365 in China that you want to migrate to.
The key factor here is where Office 365 resides, for example whether or not Office 365 is outside or inside the Chinese firewall.
The Chinese government runs and maintain the Great Firewall in China. There is an "international side" (outside the firewall) and a "mainland" side (inside the firewall).
In MSPComplete, the "Office 365 China" endpoint refers to "Office 365 China International". You can use this endpoint if you are migrating users to this international version of Office 365 in China, the version that is outside the firewall.
However, if you are migrating to Office 365 in China (inside the firewall), you should work with 21 Vianet. BitTitan has partnered with 21 Vianet to enable Partners to migrate to Office 365 in China, inside the firewall. For more information on this partnership, read the blog here.
To initiate the process, contact 21 Vianet's sales department by sending an email to firstname.lastname@example.org.