You can use Batch to send notifications to iOS users who live in China or travel there occasionally.
Batch relies on FCM/GCM to deliver notifications to your Android users in China. In order to get a device token and handle push notifications, your user device must come with a recent version of Google Play Services.
Due to local restrictions, none of the devices sold in China include Google Play Services and most of the connections to Google are blocked.
Please note these restrictions don't apply to Batch's In-App messages. In-App campaigns are a good alternative if you are not planning to use a local push provider on Android and you still want to communicate to your Chinese users.