Box 14. I have code 6 and don't know the category it corresponds to in the drop down menu that I have to choose from

Box 14 on what?  A W2?  Ask the employer what it's for.  Never heard of just a code # for box 14.  

Having a code, I would expect it to apply to box 12. However, a code 6 isn't valid for box 12 either. No clue what it means. You'll have to ask the employer or issuer of that W-2 what it means.

Code 6 for box 14 corresponds with "Other (not classified)."

After doing a little sleuthing and math, I am pretty sure that Code 6 stands for total pre-tax medical/dental/vision insurance premiums you paid.