how do I block unknown callers from 92 prefix ie Pakista

Hey there Hun12,

If the calls are being received through a third party app and not through cellular service, then try using the steps to help with blocking calls through WhatsApp below:

Block a contact

1. Open WhatsApp Settings > Privacy > Blocked > Add New...

2. Find the contact you want to block, then tap the contact.

Note:

* If you change your phone number and use the same WhatsApp account, your blocked contacts will stay blocked. Learn how to use the change number feature in this article.

* If you set up a new WhatsApp account, you’ll need to manually block those contacts again.

More ways to block a contact:

* Open the chat with the contact, then tap the contact's name > Block Contact > Block or Report Contact > Report and Block. 

* In your Chats tab, swipe the chat left, then tap More > Contact Info > Block Contact > Block or Report Contact > Report and Block.

Block an unknown phone number

To block an unknown phone number, you have two options:

* If this is the first time you've been contacted by that phone number, you can open the chat and tap Block > Block.

* Open the chat with that phone number, then tap the phone number > Block Contact > Block or Report Contact > Report and Block.

Note:

* Tapping Report and Block will both report and block the number.

* Blocked contacts will no longer be able to call you or send you messages.

* Your last seen, online, status updates, and any changes made to your profile photo will no longer be visible to contacts you've blocked.

* Blocking a contact won't remove them from your contacts list, nor will it remove you from the list on the contact's phone. To delete a contact, you must delete the contact from your phone's address book.

* If you're concerned about whether a blocked contact will know if you're blocking them, please read this article.

For more details: How to block and report contacts | WhatsApp Help Center

If the calls are also coming through the Phone app with your carrier, you'll need to reach out to the carrier directly as they will control calling and might have additional blocking features for your number.

Take care!

iPhones do not offer the ability to block calls by area code. There are, in the U.S., at least, third party apps that apparently will. Try looking at Robokiller or NoMoRoBo. I don't know if they will work with Whatsapp.