What do you mean be INTERNAL style tags?

Could you give an example of the markup you are trying to add, and what it looks like after TinyMCE have stripped away some of it?

Hi Syed,

Create an initialization module and use this code-

using EPiServer.Cms.TinyMce.Core;
using EPiServer.Framework;
using EPiServer.Framework.Initialization;
using EPiServer.ServiceLocation;

namespace ABC.Framework.Web.Business.Initialization
{
    [InitializableModule]
    [ModuleDependency(typeof(TinyMceInitialization))]
    public class TinymceCustomInitialization : IConfigurableModule
    {
        public void ConfigureContainer(ServiceConfigurationContext context)
        {
            // browser console to see settings: window.tinymce.settings;

            context.Services.Configure<TinyMceConfiguration>(config =>
            {
                config.Default()
                    .AddSetting("valid_children", "+body[style]").AddSetting("extended_valid_elements", "script[language|type|src]");
            });
        }

        public void Initialize(InitializationEngine context) { }

        public void Uninitialize(InitializationEngine context) { }
    }
   
}