Does it support mTLS while registering services to Consul ?

[EddyChina]

After registering grpc-xx services to Consul, how to support mTLS between services call?

[jvmlet]

Consul is just a service registry, so any client asking the service tagged something will get the address of the service that fullfils thesomething requirements.
From the point the client got the address of the desired service its totally up to client and service to negotiate the conversation. So I don't think Consul is in play here, if I'm not missing something.
You should implemented tls/mtls using standard grpc api/grpc starter configuration properties.