$R$ is reflection in the $y$-axis.

$S$ is rotation by ${90}^{\circ }$ clockwise about the origin.

$T$ is translation by 1 unit to the right.

$RSTI{R}^{-1}{S}^{-1}{T}^{-1}{I}^{-1}$ corresponds to a rotation by ${180}^{\circ }$ about the point $(-\frac{1}{2},-\frac{1}{2})$.