You can change several properties of remote files, including permissions (chmod) and ownership (chown, chgrp). You can change properties of one file only, set of files or even recursively for all files in selected directories.
To change properties, select files and directories and go to Files > Properties. If the server does not provide some of the file attributes in directory listing, they will be requested. Properties dialog will appear then. You can also use remote file context menu or click respective toolbar button.