htaccess not working on drupal 7 when uploaded to pantheon server

Question

My drupal site has a .htaccess file on which I am redirecting the page without changing the URL, Its working fine on local server & other servers but when I upload the files & databases to pantheon server It will not redirect the page saying 404 not found. I placed .htaccess at the root of code folder, I tried placing it in server root folder, sites folder & themes folder but nothing works for me. Can any body know what is the correct placement of .htaccess in drupal site on pantheon? & why my .htaccess not working on pantheon?