Yeah, it'll be 5 for sure
(30/36 RT cores) * (6 GigaRays) = 5 GigaRays
(There's 1 RT core per SM, or 64 CUDA cores)
We can make this assumption since RT performance isn't impacted much by the memory bandwidth & size reduction, which is the largest thing cut about this card, the clocks are negligible differences.
At the end of the day, a 15% cut shouldn't make this pointless with how strong performance has got with updates (For the 1 generally fairly intensive game we've seen so far).
I wouldn't expect this 6GB version to be tooooo far from the 2070 in most aspects, including price, because it just isn't.
They could probably get doable RT from ~4 GigaRays as time goes on(Not super distant) so I wouldn't rule out a 2060 3/4GB with another 192 cores(3 RT units or ~0.5 GigaRays worth) removed still having somewhat useful RT by the time of its launch.
I could be pedantic and say that Gigarays isn't a hardware spec but a performance characteristic, though given the number of CUDA cores we can intuit how many RT cores the RTX 2060 offers.
Given its 17% fewer CUDA cores, it would make sense that it also offers 17% fewer RT cores. With that in mind, a 5 Gigarays ball-park figure makes sense. My main reason for not including that number is that I didn't want to add any guesses into the specs list, even if they are probably accurate.
Yeah, to be fair it's not a particularly meaningful performance characteristic either, given we've no idea what test (Or calculation if it's a theoretical unit) NVidia does to get that number afaik (Actual rays/sec possible would depend on scene complexity and a variety of other factors), so it probably won't be too useful when it comes to comparing across other GPU architectures in the future.