Hello Sachin,

Version 6.0 of Kentico CMS uses CKEditor and the configuration file for CKEditor can be found in ~\CMSAdminControls\CKeditor\config.js. You should be able to modify this file to try and remove the default <br> tag which prevents the validation.

For example, to change the enter behavior, you can use this setting:

config.enterMode = CKEDITOR.ENTER_P;

instead of:

config.enterMode = CKEDITOR.ENTER_BR;

For more information about CKEditor configuration, I would like to point you to this article:http://docs.cksource.com/ckeditor_api/symbols/CKEDITOR.config.html

Another alternative would to be develop a custom form control - http://devnet.kentico.com/docs/devguide/developing_form_controls.htm - and validate the content based on some regular expression or your own custom methods.

Best Regards,
Edward Hillard