Let $G$ be a finite group, $R(G)$ be the solvable radical of $G$, and $G/R(G)$ be an almost simple group with socle $S\cong PSL_2(3^p)$, where $p$ is an odd prime. Also let $[G/R(G):S]=p$ and $\theta$ be a $G$-invariant complex irreducible character of $R(G)$ which is not extendible to $G$. What is the set of degrees of irreducible characters of $G$ lying over $\theta$.
Thanks.