You may have some events that you do not want to sync from your NetSuite calendar to your Google calendar. For each event you do not want to sync, you can check the Don’t Sync with Google box under the Custom tab on the event record. If this box is checked, the NetSuite event does not sync with your Google calendar.
If this option is enabled while creating an event, the event never syncs to Google. However, if you have enabled this option at any point after creating the event, the event would have a corresponding Google event to which it was earlier synced. However, from the time that you have enabled this option, the NetSuite event will not update the corresponding Google event nor will it be updated by any change in the corresponding Google event.
Unfortunately, this functionality is not available to block syncing specific events from Google Calendar to NetSuite.