That rod is generally used with pinch- pleated curtains with those horrible hooks. Do they still make those things? If possible I would remove the rings and replace them with " rings with clips". You can then use many types of curtains. But, you could always get a totally different decorative rod.

It's called a traverse rod and used for extra wide drapes and you can pull them open with a cord at the side.

You need pinch pleated draperies, with tops like your sheers and hooks something on the order of these:

https://www.youtube.com/watch?v=_AbcIjQ_ZPA

Unless you want to hang pinch pleated draperies with the ability to use the draw strings to open and close them, and are considering custom, it would be less expensive to just replace the rod and get ready made draperies. And would be a more current look.

or this type which I always preferred it held the drape up much better

The drapes would have looked just like the sheers underneath, pleated, but heavier fabric. Its actually a superior construction compared to what most people do now because you can open and close the drapes without ever touching or putting tension on the fabric.

The nicest hooks slide into a pocket around the pleat or are sewn in. A puternut shows the better removable kind. The types shown are functional since they can be removed for washable curtains.

Thank you so much! @palimpsest you had me "washable" :)

Wow - a vintage traversing (also called an estate) rod. If it's still working well, go ahead and keep it. If it's in your budget, you'll want pinch pleated drapes (IMHO much nicer than flat panels with clip rings). The newer drapery pins are small.

Pinch pleats. For hours of fun, you can restring the cord. This rod works very well for heavy lined pleated curtains.