can i store RAW photo files on iCloud?

If you are asking about iCloud Photo Library: Photos for Mac can store all RAW files in iCloud Photo Library that are compatible with Photos for Mac and appear in this list for High Sierra RAW Support:

Digital camera RAW formats supported by iOS 11 and macOS High Sierra - Apple Support

On iCloud Drive you can store any file you want, even unsupported RAW files, - as long as the files do not exceed the file size limit for iCloud Drive of 50GB per file.

Canon 60D - that can give you gigantic RAW files indeed.

But stick with the Canon RAW format and do not used the compressed versions of the RAW format, if you want to use iCloud Photo Library. As you can see in the footnotes at the bottom of the list, Apple's RAW support is usually only supporting the uncompressed versions of RAW files.

yes

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Do you want to store the photos on iCloud drive as referenced originals to be used as part of a Lightroom catalog? I do not use Lightroom, so I cannot say, if the links between the originals on iCloud drive and your Lightroom catalog will survive the syncing on iCloud Drive. Check the user guide, if it is safe to store the photos on iCloud Drive. If you just use iCloud Drive to transfer the photos but not as a permanent storage it will be safe.

I'm using iCloud Drive for files that need on all my Macs and want to to updated across all devices, when I am working on them. I'mnot using it as a backup or as an external storage, just to have the important documents I am currently working on synced across all devices. And since all three Macs are backing up to Time Machine, I have three independent Time Machine backups of my important documents.