Hello @kumar.neeraj,
Is there anything that has changed since you got the system working with @MartinLangmaid in this previous forum thread?
We gather you have checked both of your PepVPN & IPSec settings.
You can make changes to check with out commiting them into operation if you wish to this area of the router, try using a different subnet and see if you get the same error, to discard your changes, just go back to the Dashboard tab, scroll down to the bottom and select “Discard Changes”.
Happy to Help,
Marcus 