SharingTerritoryRule should be used to retrieve Territory Sharing Rules.
package.xml:
<?xml version=”1.0″ encoding=”UTF-8″?>
<Package xmlns=”http://soap.sforce.com/2006/04/metadata”>
<types>
<members>*</members>
<name>SharingTerritoryRule</name>
</types>
<version>52.0</version>
</Package>
<Package xmlns=”http://soap.sforce.com/2006/04/metadata”>
<types>
<members>*</members>
<name>SharingTerritoryRule</name>
</types>
<version>52.0</version>
</Package>