Which three message types are used for prefix delegation in DHCPv6?

DHCPv6 Message Types
For a client to get an IPv6 address successfully from a DHCPv6 server, the Client-Server
Conversation happens using the following messages.
Client—>Server Messages
Server—>Client Messages
Solicit, Request, Confirm, Renew, Rebind, Release, Decline, Information-Request
Advertise, Reply, Reconfigure
Lets look at each message types in detail :
SOLICIT
This is the first step in DHCPv6, where a DHCPv6 client sends a Solicit message to locate
DHCPv6 servers.
ADVERTISE
Upon receiving a Solicit Message from the client, the DHCPv6 server sends an Advertise
message to indicate that it is available for DHCP service, in response to a Solicit message
received from a client.
REQUEST
This message is sent by the DHCPv6 client.Client sends a Request message to request
configuration parameters which includes IP addresses or delegated prefixes, from a specific
server.
CONFIRM
Confirm message is sent by the client to any available server in the network to confirm that the
client is still on the same link or it has to be removed. This message also confirms the IPv6
addresses that are assigned to the link are still valid. This could happen in case when a client
detects a change in link-layer connectivity or if the device is powered on and it is found that one or
more leases are still valid. Note that only the prefix portion of the addresses are validated and not
the actual leases.
RENEW
A client sends a Renew message to the server when it wants to extend the lifetimes on the
addresses and other configuration parameters assigned to the client and also to update other
configuration parameters.
REBIND
In case of No response from the DHCPv6 Server for the Renew message, the client sends a
Rebind message to any available server to extend the lifetimes on the address and to update
other configuration parameters.
REPLY
A Reply message is sent by the DHCPv6 Server in response to a Solicit, Request, Renew, Rebind
message received from a client. The reply message is sent by the server in response to a confirm
message (either confirming or denying) that the addresses assigned to the client are
appropriate.In short the server acknowledge receipt of a Release or Decline message by sending
a REPLY message.
RELEASE
Release message as the name implies, is sent by the client to the server that has assigned the
addresses, to indicate that the client will no longer use the assigned addresses(one or more).
DECLINE
Client sends a Decline message to the DHCPv6 server to tell that the one or more addresses
assigned by the server is already in use
RECONFIGURE
The Reconfigure Message is sent by the DHCPv6 server to the client when the server has new or
updated information of configuration parameters. It tells the client to initiate a informationrequest/
reply message to the server so as to receive the updated information.
INFORMATION-REQUEST
Information-Request message is sent by the client to the server to update the configuration
parameters
Reference. https://supportforums.cisco.com/blog/153426/implementing-dhcpv6-introduction