Concept:
A system of two linear equations in two unknowns has a unique solution if the determinant of the coefficient matrix is non-zero.
Step 1: Write coefficient matrix.
The equations are
\[
6x-2y=3
\]
\[
kx-y=2
\]
The coefficient matrix is
\[
A=\begin{bmatrix}
6&-2
k&-1
\end{bmatrix}
\]
Step 2: Find determinant.
\[
\det A=6(-1)-(-2)k
\]
\[
=-6+2k
\]
\[
=2k-6
\]
Step 3: Unique solution condition.
For a unique solution,
\[
\det A\neq 0
\]
\[
2k-6\neq 0
\]
\[
2k\neq 6
\]
\[
k\neq 3
\]
Step 4: Final answer.
\[
\boxed{3}
\]