Hello,
to setup JoomSEF correctly, you RewriteBase should be set to /evyne/joomla then.
RewriteBase /evyne/joomla
If you will still get the error message, it might be some problem with Apache configuration where .htaccess file may be prohibited or some other similar reason. "Forbiden" error is not so often though, usually with wrong .htaccess configuraiton is either "Page does not exists" when RewriteBase is wrong or "Internal server error" when there is some misspelling in .htaccess.
The "forbidden" could be also the problem of wrong "RewriteBase" trying to put you to different directory, where you do not have permissions.
Regards,
Michal