if we do not configure HSRP or another protocol ,How data will flood if there is redundancy ? please help me I need some explain about load balancing
How the data will flood (if it will) depends on the design. If there it is a complete L2 network, then by the routes on the host it will forward the packets to the gateway. For that it needs the MAC of the gateway. If both gateways have the same IP, then the gateway that replies first for the ARP is selected. If they have different Ip then the gateway that is configured at the host will reply.
In the layer 3 network. it depends on the discretion of the routing protocol. If BGP is used than the admin has the flexibility of choosing the gateway.