Operater can get damaged while in rift.

[NeirdAE]

I was using Limbo to try to unlock a Riven mod that required a defense mission to be completed alone without the target taking damage. I had Cataclysm over the objective, and I found that my Operator's Amp could hit enemies outside the Rift, while standing under Cataclysm. However, enemies could damage me as well, and if an enemy got into the rift and frozen with Stasis, my operator could not damage it. This was on Outer Terminus, Pluto, if that helps.

[Invisibleaxeman]

Operators are rift proof, they don't actually enter the rift.