I am using magento 2.4 enterprise edition. Products I can generate return requests are of type Simple ,Grouped, Bundled. This is default feature supported by magento. Though I wonder why it is not supported for configurable product? Is there any way to do so?
After debugging for while I found that, weight in simple product/child product was missing of my configurable product which I added in cart. So it was not showing me shippping option on checkout page.
Hence in first time I placed order withoug shipping method so product was not able to ship. And product which cant be shipped cant be managed for RMA.
Now as I added this weight shipping option is also visible . And once product will be shipped from admin by admin customer can generate RMA for this configurable product too.