Hi Summit, in addition to what Johan has outlined above,
A VLAN will only request an IP address from a DHCP server that is configured globally, or explicitly enabled on that particular VLAN. In the two commands below, the first command adds a DHCP server to the vlan v1_vlan meaning, the switch can attempt to solicit an IP address from 192.168.0.1 for any client within v1_vlan. In the second command, the DHCP server 10.0.0.1 is enabled globally. What this means is that the clients in v1_vlan now have access to a second DHCP Server (10.0.0.1).
configure bootprelay "v1_vlan" add 192.168.0.1
configure bootprelay add 10.0.0.1
Whether or not an IP address will be assigned to a client is not important at this stage, because the DHCP server has the responsibility to assign the correct IP address in the correct subnet by choosing the DHCP DISCOVER packet to respond to. Similarly, the DHCP client is responsible for accepting the appropriate DHCP OFFER from the DHCP server. Extreme's switches handle multiple DHCPs configured for a single VLAN using Sequential mode where the switch relays a DHCP DISCOVER packet for the first IP. If there is no offer from the Server after three tries, the Switch then attempts the second IP until an offer is received.
I hope the above answer two of your questions. Finally, you'd have to elaborate a little further on how you've deployed VRRP. In an idea situation that would be an entirely different set of devices altogether, and if they are, then the DHCP packets simply transit through them enroute to the DHCP Server
