FTP uploads are limited to 200MB per file. If you really need to use a larger file than this in your web space, you will need to split it into chunks and reassemble them after uploading/downloading them separately. To do this, you should use a spanned ZIP file, functionality which is supported by all popular archiving software.

Please note, individual packages do have a monthly softcap of 25gb for file distribution (i.e. non-browsing traffic), please do not intentionally bypass this limit if your intention is to run a large file distribution service.