V-Ray versions are lower than 3.1, be careful, in the materials in the BRDF section there is Microfacet GTR (GGX), if your version is older than 3.1, then the BRDF field will be empty. Choose Blinn, Phong, or Ward - whichever suits you best.

For Corona Render, it is recommended to install a version of at least 1.5, since the glossiness of materials is configured with PBR in mind.