Curtains with goblet pleats and internal ornamental trimmings, tulle and Roman shade with trimming.
The scene includes a simplified window model and a simplified cornice model.

The curtain set is grouped for convenience. In the export file, the objects are ungrouped.
The colors of the model can be changed in the material settings.

https://3dsky.org/collection/shared/5255126  collection of my curtains.

For Corona render, it is recommended to use version no lower than 1.5, as the glossiness of the materials is set with PBR in mind.

If you are working in V-Ray version lower than 3.1, be careful, in the materials section BRDF is set to Microfacet GTR (GGX), if your version is older, the BRDF field will be empty. Choose Blinn, Phong, or Ward – whichever is preferable for you.