Is it a pack of tic tacs or a box of tic tacs?

Answer 1

I would say a pack because it is primarily plastic and not cardboard as most boxes are made of.
Divergent answer: I have to disagree that boxes are primarily cardboard. Many boxes are constructed of wood, metal, glass, and yes, plastic. My mother for years had an alabaster (that's a type of salt) box she kept on the mantel.

A box is, afterall, a container constructed with four sides perpendicular to the base and often being fitted with a top or lid. The material from which it is constructed is of no particular import other than to what is stored within it or to what purpose it is put. It would be silly to construct a box from, say, alabaster if the intended purpose was to use it to bail water from a boat. Although, one typically uses a bucket for such purposes as bailing, but I digress.

Since a Tic Tac container has four sides that can be described as perpendicular to the base, and it has been fitted with a top or lid, it is by definition a box.

However, the bundle in which a collection of Tic Tac boxes is delivered may be referred to correctly as a pack.