Answer
The remaining zeros are:
$\color{blue}{\bf2-i, -3+i}$
Work Step by Step
RECALL:
If $a+bi$ is a zero of a polynomial function with a real number of coefficients, then its conjugate, $a-bi$, is also a zero of the function.
Thus, the missing zeros of the given function are the conjugates of $2+i$ and $-3-i$, which are:
$\color{blue}{\bf2-i, -3+i}$