\usetikzlibrary{positioning}
\begin{center}
%\fbox{
\begin{tikzpicture}
	\begin{scope}[
		box1/.style={draw=black, thick, rectangle,rounded corners, minimum height=0.75cm, minimum width=0.75cm}]
\draw[black,dashed,fill=red!30] (-.5,-3.2) rectangle (3.2,.5);
\node[box1, fill=green!30] (c1) {};
\node[box1, fill=green!30, right=.125cm of c1] (c2) {};
\node[box1, fill=green!30, right=.125cm of c2] (c3) {};
\node[box1, fill=green!30, right=.125cm of c3] (c4) {};
\node[box1, fill=green!30, below=.125cm of c4] (c5) {};
\node[box1, fill=green!30, left=.125cm of c5] (c6) {};
\node[box1, fill=green!30, left=.125cm of c6] (c7) {};
\node[box1, fill=green!30, left=.125cm of c7] (c8) {};
\node[box1, fill=green!30, below=.125cm of c8] (c9) {};
\node[box1, fill=green!30, right=.125cm of c9] (c10) {};
\node[box1, fill=green!30, right=.125cm of c10] (c11) {};
\node[box1, fill=green!30, right=.125cm of c11] (c12) {};
\node[box1, fill=green!30, below=.125cm of c12] (c13) {};
\node[box1, fill=green!30, left=.125cm of c13] (c14) {};
\node[box1, fill=green!30, left=.125cm of c14] (c15) {};
\node[box1, fill=green!30, left=.125cm of c15] (c15) {};
		\end{scope}
\end{tikzpicture}
%}
\end{center}