I want to handle the responses for forked Requests in kamailio.

Please suggest me that where i can handle this in configuration. 

Here is my requirement.

If Clinet A is registered with kamailio server on pc 1 and pc 2. If Client B calls A, Server is sending INVITE to A for both PC 1 and PC 2. 

As per current implementation Server closing the INVITE session if any one(pc1/pc2) responds with 486.

But i want to handle the 486 response, and wait till other one(pc1/pc2) also responds instead of closing INVITE session. 

Regards,

Raman