Step 1: Use the condition that \((\alpha,-\alpha)\) lies inside the ellipse.
The ellipse is
\[
4x^2+5y^2=1.
\]
Since \((\alpha,-\alpha)\) is an interior point,
\[
4\alpha^2+5(-\alpha)^2<1.
\]
\[
4\alpha^2+5\alpha^2<1.
\]
\[
9\alpha^2<1.
\]
\[
\alpha^2<\frac{1}{9}.
\]
\[
-\frac13<\alpha<\frac13.
\]
Step 2: Find the length of the interval.
Thus \(\alpha\) belongs to the interval
\[
\left(-\frac13,\frac13\right).
\]
Hence the length of the interval is
\[
\beta=\frac13-\left(-\frac13\right)
=\frac23.
\]
Step 3: Evaluate \(6\beta-4\).
\[
6\beta-4
=
6\left(\frac23\right)-4.
\]
\[
=4-4.
\]
\[
=0.
\]
Step 4: Evaluate the given expression.
\[
(6\beta-4)^{201}+201
=
0^{201}+201.
\]
\[
=201.
\]
Step 5: Final conclusion.
Therefore,
\[
\boxed{201}
\]