diff --git a/manila/share/drivers/netapp/dataontap/client/client_cmode_rest.py b/manila/share/drivers/netapp/dataontap/client/client_cmode_rest.py
index e5645977cd..c51c45b048 100644
--- a/manila/share/drivers/netapp/dataontap/client/client_cmode_rest.py
+++ b/manila/share/drivers/netapp/dataontap/client/client_cmode_rest.py
@@ -2589,14 +2589,9 @@ class NetAppRestClient(object):
         }
 
         if autosize_attributes:
-            attributes = autosize_attributes
-            body['autosize'] = {
-                'mode': attributes['mode'],
-                'grow_threshold': attributes['grow-threshold-percent'],
-                'shrink_threshold': attributes['shrink-threshold-percent'],
-                'maximum': attributes['maximum-size'],
-                'minimum': attributes['minimum-size'],
-            }
+            autosize = self._build_autosize_attributes(autosize_attributes)
+            if autosize:
+                body['autosize'] = autosize
 
         if language:
             body['language'] = language
@@ -2639,6 +2634,35 @@ class NetAppRestClient(object):
         if self._is_snaplock_enabled_volume(volume_name):
             self.set_snaplock_attributes(volume_name, **options)
 
+    @na_utils.trace
+    def _build_autosize_attributes(self, autosize_attributes):
+        """Build autosize attributes dict from autosize_attributes."""
+        reset_val = autosize_attributes.get('reset', '')
+        if str(reset_val).lower() == 'true':
+            return None
+
+        src = autosize_attributes
+
+        # Build autosize dict directly
+        autosize_key_map = {
+            'grow-threshold-percent': 'grow_threshold',
+            'shrink-threshold-percent': 'shrink_threshold',
+            'maximum-size': 'maximum',
+            'minimum-size': 'minimum',
+        }
+
+        autosize = {
+            dest_key: src[src_key]
+            for src_key, dest_key in autosize_key_map.items()
+            if src_key in src
+        }
+
+        # Add mode if present
+        if 'mode' in src:
+            autosize['mode'] = src['mode']
+
+        return autosize if autosize else None
+
     @na_utils.trace
     def start_volume_move(self, volume_name, vserver, destination_aggregate,
                           cutover_action='wait', encrypt_destination=None):
diff --git a/manila/tests/share/drivers/netapp/dataontap/client/test_client_cmode_rest.py b/manila/tests/share/drivers/netapp/dataontap/client/test_client_cmode_rest.py
index 8bb2af29b2..972b792a1f 100644
--- a/manila/tests/share/drivers/netapp/dataontap/client/test_client_cmode_rest.py
+++ b/manila/tests/share/drivers/netapp/dataontap/client/test_client_cmode_rest.py
@@ -2488,6 +2488,89 @@ class NetAppRestCmodeClientTestCase(test.TestCase):
                           self.client._parse_timestamp,
                           test_time_str)
 
+    def test__build_autosize_attributes(self):
+        """Test _build_autosize_attributes with various input scenarios."""
+
+        # Test case 1: Basic functionality with all supported attributes
+        autosize_attrs = {
+            'grow-threshold-percent': 90,
+            'shrink-threshold-percent': 50,
+            'maximum-size': '10GB',
+            'minimum-size': '1GB',
+            'mode': 'grow'
+        }
+
+        result = self.client._build_autosize_attributes(autosize_attrs)
+
+        expected = {
+            'grow_threshold': 90,
+            'shrink_threshold': 50,
+            'maximum': '10GB',
+            'minimum': '1GB',
+            'mode': 'grow'
+        }
+        self.assertEqual(expected, result)
+
+    def test__build_autosize_attributes_reset_true(self):
+        """Test _build_autosize_attributes returns None when reset is true."""
+        autosize_attrs = {
+            'reset': 'true',
+            'grow-threshold-percent': 90,
+            'maximum-size': '10GB'
+        }
+
+        result = self.client._build_autosize_attributes(autosize_attrs)
+
+        self.assertIsNone(result)
+
+    def test__build_autosize_attributes_partial_attrs(self):
+        """Test _build_autosize_attributes with only some attributes."""
+        autosize_attrs = {
+            'grow-threshold-percent': 85,
+            'maximum-size': '5GB'
+        }
+
+        result = self.client._build_autosize_attributes(autosize_attrs)
+
+        expected = {
+            'grow_threshold': 85,
+            'maximum': '5GB'
+        }
+        self.assertEqual(expected, result)
+
+    def test__build_autosize_attributes_empty_dict(self):
+        """Test _build_autosize_attributes returns None for empty dict."""
+        autosize_attrs = {}
+
+        result = self.client._build_autosize_attributes(autosize_attrs)
+
+        self.assertIsNone(result)
+
+    def test__build_autosize_attributes_with_mode_only(self):
+        """Test _build_autosize_attributes with only mode attribute."""
+        autosize_attrs = {
+            'mode': 'grow_shrink'
+        }
+
+        result = self.client._build_autosize_attributes(autosize_attrs)
+
+        expected = {
+            'mode': 'grow_shrink'
+        }
+        self.assertEqual(expected, result)
+        autosize_attrs = {
+            'grow-threshold-percent': 90,
+            'maximum-size': '10GB'
+        }
+
+        result = self.client._build_autosize_attributes(autosize_attrs)
+
+        expected = {
+            'grow_threshold': 90,
+            'maximum': '10GB'
+        }
+        self.assertEqual(expected, result)
+
     def test_start_volume_move(self):
 
         mock__send_volume_move_request = self.mock_object(
diff --git a/releasenotes/notes/bug-2130717-auto-attribute-mode-key-error-for-rest-e7958807a5e2e0e5.yaml b/releasenotes/notes/bug-2130717-auto-attribute-mode-key-error-for-rest-e7958807a5e2e0e5.yaml
new file mode 100644
index 0000000000..f06a3a6dcb
--- /dev/null
+++ b/releasenotes/notes/bug-2130717-auto-attribute-mode-key-error-for-rest-e7958807a5e2e0e5.yaml
@@ -0,0 +1,9 @@
+---
+
+fixes:
+  - |
+    Fixed an issue that caused the share replica promotion to fail due to
+    missing replica attributes in the NetApp driver while using the REST API.
+    For more details, please refer to
+    `launchpad bug #2130717 <https://bugs.launchpad.net/manila/+bug/2130717>`_.
+