How to develop Radius Proxy Service to intercept and route to underline Radius Servers for AAA requests

Question

I am pretty new to this Radius concept. Need some help and ideas on how to handle the below use case and what opensource libs can be helpful.

We have many devices that are doing RADIUS MFA with RSA SecurID, working on bringing Symantec also want to have a proxy in between these vendors to intercept & inspect Radius traffic and based on some logic want to route to Symantec or RSA for all AAA calls.

Any help in developing this proxy will help and what are some of the opensource products I can leverage. Want to make sure can handle the load as the number of requests could be in hundreds per/sec, and want it to be highly available.

Thanks