You question is very difficult to understand, please try to be more specific so we can better answer your question.
To answer: I’m quite certain your router can’t handle multiple DHCP…in which case getting both incoming lines to work and broadcast through one router is not going to happen.
i think you are referring to loadbalancing. In this can the traffic is distributed among multiple L3 links.
please enable “cef” on the router and it will take care of loadbalancing.
refer to the below link for details: