Hi Anamika,
If you are blocking a single country code only, there's no need to perform regex as regex is meant to transform the number to a different format and pass it out of your trunk. (e.g. from +44xxxxxxx to 0044xxxxxxx)
Because you want to block these numbers for outbound, there's no need to transform and normalize the number.
Simply create a new number plan entry and keep it at the top of the list. Classify it as restricted.
Notes:
- You can enter multiple country codes separated by comma. Can also do a range (e.g. 1-971)
- This works assuming that users dial in E.164 format
- If users dial numbers in non-e.164, it will always attach the site's location as the default country code during normalization.
(e.g. site with location in US/Canada will have +1 country code even if they enter 44xxxxxxx to dial a UK number)

Number plan information - Genesys Cloud Resource Center (mypurecloud.com)
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Niel Vicente
DAMAC Properties Co. LLC
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