For a railroad employee in box 14 description RR MEDWAGE what do i use in the drop down box for the catagory?

It depends on the version of Turbo Tax you are using.  I tested Turbo Tax Online and there is a category in the drop down for Railroad Retirement Medicare Tax if that is what you are referring to. I am not familiar with RR Medwage or can't find a reference to it. I think Railroad Retirement Medicare Tax is what you need to choose as a drop down.

Its the "wage" part of Medwage that concerns me.   

If the $$ amount is somewhere close or equal to the box 1 value, then I would guess it's in the Railroad Retirement Compensation category.   But if it IS the Medicare tax, then the $$ listed for that would be a much smaller number....approx 1.45% of your wages