The answer to this question is not simply turboprop vs. turbojet...

What type of flying is involved? I have seen plenty of 121 t-prop people get hired at majors, as well as military folks. Part 135 and part 91 are less valuable. There are plenty of folks at amflight who aren't getting hired by majors, they keep turning up at my regional.

What type of turboprop? Larger is probably better. Newer (glass) is probably good too. Some military guys have only flown t-props (P3, C-130, etc)...those guys have no problems getting hired as a rule.

If all other things were exactly equal with two applicants, they would probably pick the turbojet driver simply because he is a lower training risk, since he has already completed training in a similar airplane.

Assume that caravan time will NOT work...it has about the same value as CE-172 time. I know, none of the majors specify ME turbine time...but that is only because F-16s and AV8Bs are single-engine turbine. Caravan flying has no track record of leading to the majors.