Alright, so here's the deal. Firebase Storage doesn't have a built-in option for multi-region redundancy. It relies on Google Cloud Storage, where you can pick a storage class when you create a bucket. But, once that bucket's set up, you can't change its class or location. So, if you want multi-region redundancy, you'll need to go straight to Google Cloud Storage.

1. Head over to the Google Cloud Console.
2. On the left sidebar, click 'Storage' and then 'Browser'.
3. Hit the 'Create Bucket' button.
4. Give your bucket a unique name.
5. Set the location type to 'Multi-Region'.
6. Pick your preferred multi-region location.
7. Adjust any other settings you need and click 'Create'.

Now, let's tell Firebase to use this new multi-region bucket instead of the default one.

1. Open your Firebase Console and go to your project's settings.
2. On the left sidebar, click 'Storage'.
3. Click the 'Add bucket' button.
4. In the 'Select a Cloud Storage bucket' dialog, choose 'Select a different bucket' and enter the name of the bucket you just created in Google Cloud Storage.
5. Confirm adding the bucket. Firebase will now use this multi-region bucket for storage.

Firebase only lets you set custom rules for the default bucket. So, if you want custom rules for your new bucket, you'll need to update the Firebase Storage rules manually.

1. In the Firebase Console, go to 'Storage', then click on 'Rules'.
2. In the 'Rules' text editor, add custom rules for your bucket by adding another match block like this:

service firebase.storage {
  match /b/{bucket}/o {
    match /{allPaths=**} {
      allow read, write: if <Your_Condition>;
    }
  }
  match /b/your-newly-created-bucket.appspot.com/o {
    match /{allPaths=**} {
      allow read, write: if <Your_Condition>;
    }
  }
}

Replace <Your_Condition> with your rule condition. The first match block is for the default bucket, and the second one is for the new bucket.

And there you have it! Firebase Storage is now set up for multi-region redundancy. Just remember, Firebase doesn't natively support this, so you'll need to manage the bucket in Google Cloud Storage.