I have below EEPC server configuration and on that already 25000/00 licenses are thr.
Intel R XEON(R) CPU, 2.40 GHZ, 16 GB RAM.
So just want to know that up-to how many licsense i can upgrade on this mention server for e.g (40000/00,50000/00)
It's really imposible to say - the number of licences does not really make a difference, it's the number of machines trying to sync concurrently - that's the limiting factor.
If your server is happy at the current load, all you can really do is keep deploying machines until it starts to show a high load, then buy proportionally faster equipment.