Exclude a category id from category collection in Magento
Please use the below code for exclude a category id from category collection in Magento
<?php
$allCategories = Mage::getModel('catalog/category')
->getCollection()
->addAttributeToSelect('*')
->addAttributeToFilter('level',2)
->addAttributeToFilter('entity_id', array('nin' => 69))
->addIsActiveFilter();
?>