I have a batch process which makes a HTTP call out to third party, but because of IP restriction third party is denaying the request.
Is there any way to get Salesforce server Client IP from where this callout is making?
Salesforce publishes the IP ranges for their networks.
They recommend whitelisting the entire range set:
Please be reminded that our best practice and recommendation is to whitelist the entire list of Salesforce IP ranges for seamless access.
Since your Salesforce org does not have its own static IP and can change instance.
Salesforce does not have static IP address and hence you have to whitelist all IP's which are mentioned in this link.