Hello Raghu
When configuring DHCP pools for use with stateless DHCP, the DHCP server is not actually managing IPv6 addresses. It is just providing supplementary information such as DNS server addresses to the stateless clients. Since no actual IPv6 addresses are being provided by the DHCP pool, the “active client” number remains zero. An active client is only one for which IPv6 addresses are actively managed.
I labbed this one up as well just to verify.
I hope this has been helpful!
Laz