ayeshaahmed
Hi
None of module expect Joomla custom comes with this support by default. You need to edit module make some tests to check this out as this need customization in the code to allow content load
like its defined for Joomla custom html module as its core Joomla module.
/administrator/modules/mod_custom/mod_custom.php and xml file
if ($params->def('prepare_content', 1))
{
JPluginHelper::importPlugin('content');
$module->content = JHtml::_('content.prepare', $module->content, '', 'mod_custom.content');
}
Edit the sidenew module in the same way and define the code it works.
Or you can ask the extension provide whose code you are using to allow the tags in 3rd party modules.