*Partial answer* The second fusion ring admits no *unitary* categorification. It is proved in [this paper][1], using Character Table and Fourier Analysis. Here are some explanations: Let $\mathcal{F}$ be a commutative fusion ring. Then its fusion matrices $(M_i)$ are commuting and normal so simultaneously diagonalisable: there is an invertible matrix $P$ such that $P^{-1}M_iP = diag(\lambda_{i,j})$. Let us call $\Lambda=(\lambda_{i,j})$ the *character table* of $\mathcal{F}$. Note that if $G$ is a finite group and $\mathcal{F}$ the Grothendieck ring of $Rep(G)$ then $\Lambda$ is the usual character table of $G$. If $\mathcal{F}$ is the Grothendieck ring of a unitary fusion category, and if we choose $\lambda_{i,1}$ to be $\Vert M_i \Vert$, then by Corollary 7.5 in [this paper][1], for every triple $(j,k,\ell)$ $$\sum_i \frac{\lambda_{i,j}\lambda_{i,k}\lambda_{i,\ell}}{\lambda_{i,1}} \ge 0.$$ Note that for $Rep(G)$ this identity admits a combinatorial/probabilistic interpretation (see [here][2]). Now observe the character table of the second fusion ring above, in particular its last column, then $$ \frac{1^3}{1} + \frac{0^3}{5} + \frac{0^3}{5} + \frac{0^3}{5} + \frac{1^3}{6} + \frac{(-3)^3}{7} + \frac{2^3}{7} = -\frac{65}{42}<0.$$ It follows that the second fusion ring above admits no unitary categorification. Note that the identity holds for the first fusion ring. [1]: https://arxiv.org/abs/1910.12059v1 [2]: https://mathoverflow.net/q/344968/34538