For private accounts: Only your approved followers can see and share your reels. When someone shares your reel, only your followers will be able to see it. No one will be able to record a reel using your original audio or text or remix your reel.

What is an Instagram Reel? A Reel is an Instagram feature that allows users to film or upload video clips for up to 60 seconds that they can edit, sound dub, or add effects to before sharing on the app. These short video clips let users publish creative content, showcase personality, market brands, or just have fun.

For the pending question "can you see who watched your reels on Instagram"', the answer is no. Instagram doesn't reveal what profiles have seen a reel, however, you can know how many views it has. It's also possible to see the number of likes and choose if you want to show this information or not.