If you want to forward IP broadcasts of UDP port 6002 from a source on one end of a Frame Relay connection to a destination on the other end of the Frame Relay connection then you will need a combination of 2 commands: ip helper-address and ip forward-protocol. And you might need a third command. You are correct that by default routers do not forward broadcasts. But these commands can create exceptions to this rule.
You would configure ip helper-address on the router interface which is receiving the broadcasts from the source and in the command you would put the destination address to which it will be forwarded. You can put a unicast IP address (forward to a specific host) or you can put a subnet broadcast address (directed broadcast).
You would configure ip forward-protocol to identify that you want to forward UDP 6002.
If you have configured the helper address with a subnet broadcast address then on the router where the packets are delivered to the destination you would also need to configure ip directed-broadcast (which is disabled by default in current versions of code).
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...