4
That is a loaded question and depends on many things. The one sure way if you are on a hosted system is with your FTP client. You should have options to set file permissions of files even after they are uploaded. You will have to look at your FTP client to find it, each one does it differently. If you don't have those options you need a better client.
The client might not show the rights as a 0777 for example and might use dumber terminology. 777 means read,write,execute by all users. 444 is read-only for all users. 644 would be read/write by the file owner (you) and read-only for the user group and everyone else.