Iray Optix

VEGA

Does anyone know if there will be support for RT Cores in OptiX Prime (low level API) or will be supported only in OptiX as now will be in OptiX 5.2 .

Kitsumo

It's probably best to check out one of the threads already going:

Iray - Titan X, Titan V, 1080Ti vs 2080/1180 RTX? (Turing Discussion)

OT: New Nvidia Cards to come in RTX and GTX versions?! The Reviews are Trickling In..

Only Nvidia knows for sure. They build the cards, they made Optix, and they made Iray. Anything else is rumor and speculation.