Hi Kunald007
welcome to the Apple (user-to-user) Community.
Re: Siri unable to access contacts when placing a call
Wondering whether your iPhone may need updating to the latest iOS 17 version:
You can check in Settings > General > Software updates to see if there is an update to install.
About iOS 17 Updates - Apple Support shows iOS 17.6 is the latest version, and
"This update provides important bug fixes and security updates and is recommended for all users".
You may also want to also check whether your whatsapp version is up-to-date, for the best compatibility.
Eg: Whatsapp at: https://faq.whatsapp.com/3181431452166375 says that a new version is coming that everyone will get eventually, and to: "Please make sure to keep WhatsApp updated to the latest version in the meantime"
If needed, see how to check or: Change Siri accessibility settings on iPhone - Apple Support
All the best :-)