Will an apple watch ultra from Polan work in Israel cellular phone network

https://www.apple.com/watch/cellular

lists the models for different countries. The Israel and European versions should work.

NOTE: the warranty is not international, and there are some country specific features that are disabled depending on where the Apple Watch was purchased, so check the feature availability list

https://www.apple.com/watchos/feature-availability/

There are two types of cellular Watch manufactured

1. American market watches
2. Non American market watches

Check for israeli providers

Apple Watch - Carriers - Apple