We refer to Chapter 8 of the book Tensor Categories for notions related to modular tensor categories and J.P. Serre for the basic theory of linear representations of finite groups over $\mathbb C$.

Let $G$ be a finite group, $\mathrm{Vec}_G^\omega$ be a category of finite dimensional $G$-graded vector spaces (potentially twisted by some non-trivial 3-cocycle $\omega$) and $\mathrm{Rep}(G)$ be the category of finite dimensional complex (for ease) semi-simple representations of $G$. The fusion rules of $\mathrm{Vec}_G^\omega$ (resp. $\mathrm{Rep}(G)$) are given by the product of elements (resp. irreducible characters) of $G$.

The number of conjugacy classes of $G$ (the class number) is equal to the number of its irreducible characters, but there is no "natural" bijection between these two sets (see this post), in particular, the character ring is not equivalent to the conjugacy class ring in general, but note that the equivalence holds in a specific case mentionned here, properly containing the abelian groups.

Two fusion categories are said to be 'Grothendieck equivalent' if their Grothendieck rings (i.e. the de-categorification of their monoidal structure) are equivalent as fusion rings. Let $A$ be a finite abelian group, then $\mathrm{Vec}_A^\omega$ and $\mathrm{Rep}(A)$ are Grothendieck equivalent.

Example 8.13.5 of 1 mentions way to make a modular tensor category using a finite abelian group $A$ and a non-degenerate quadratic form $q: A \rightarrow \mathbb C^*$. It is denoted $\mathcal C(A, q)$ and (see on page 205) is Grothendieck equivalent to $\mathrm{Rep}(A)$.

Thus, for every finite abelian group $A$ on which there exists a non-degenerate quadratic form, $\mathrm{Rep}(A)$ is Grothendieck equivalent to a modular tensor category. But it exists for everyone according to the answers of this post.

**Question**: Is there a classification or a group-theoretical characterization of the finite groups $G$ such that the tensor category $\mathrm{Rep}(G)$ is Grothendieck equivalent to a modular category? Is there a non-abelian one?

The paper On the classification of weakly integral modular categories shows that all integral modular categories of rank at most $7$ are pointed. It follows that for all non-abelian finite group $G$ of class number at most $7$ (as $S_3$ or $A_5$), $\mathrm{Rep}(G)$ is not Grothendieck equivalent to a modular category.

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