How do I upload files through FTP when my domain is under propagation ?
You can upload files through FTP when your domain under propagation also.
You need to use server IP address instead of ftp.yourdomain.com as Host Name.
Configuration when domain under propagation:
For example :
HOST NAME : 216.119.152.247
USER ID : username
PASSWORD : your hosting domain password
After you login to your FTP account make sure that you upload your html, images and scripts etc in your public_html or www directory.