\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{plotmarks}
\usepackage{amsmath,amssymb}
\begin{filecontents}{1.data}
#MOPS 	Power [mW]
2		6.937
5		6.619
7		6.395
10		7.269
\end{filecontents}

\begin{filecontents}{2.data}
# MOPS 	Power [mW]
2		6.293
5		5.493
7		5.636
10		5.38
\end{filecontents}
%
\begin{filecontents}{3.data}
#MOPS 	Power [mW]
2		6.644
5		6.123
7		5.813
10		5.699
\end{filecontents}
%
\begin{filecontents}{4.data}
# MOPS 	Power [mW]
2		3.588
5		3.552
7		3.4
10		3.375
\end{filecontents}

\begin{document}
\begin{table}[!ht]
\caption{SA result in different number of generated solution }
\label{tab:1}
\centering
\begin{tabular}{c c c c c}
\hline 
& J30 &J60&J90&J120 \\ 
\hline 
20 & 0.6937 &0.6293&0.6644&0.3588 \\ 
50 & 0.6619 & 0.5493&0.6123&0.3552\\ 
70 & 0.6395& 0.5636&0.5813 &\\
100& 0.7269&0.5380&0.5699&0.3375\\
\hline 
\end{tabular}
\end{table}
\begin{tikzpicture}[y=0.3cm, x=.7cm,font=\sffamily]
 	%axis
	\draw (0,0) -- coordinate (x axis mid) (10,0);
    	\draw (0,0) -- coordinate (y axis mid) (0,10);
    	%ticks
    	\foreach \x in {0,...,10}
     		\draw (\x,1pt) -- (\x,-3pt)
			node[anchor=north] {\x0};
    	\foreach \y in {0,2,4,...,10}
     		\draw (1pt,\y) -- (-3pt,\y) 
     			node[anchor=east] {\y}; 
	%labels      
	\node[below=0.8cm] at (x axis mid) {\#generated solutions};
	\node[rotate=90, above=0.8cm] at (y axis mid) {Relative delay};

	%plots
	\draw [blue] plot[only marks,mark=*, mark options={fill=white}] 
		file {1.data};
	\draw [red] plot[only marks,mark=triangle*, mark options={fill=white} ]  
		file {2.data};
	\draw [green] plot[only marks,mark=square*, mark options={fill=white}]
		file {3.data};
	\draw plot[only marks,mark=square*]
		file {4.data};  
    
	%legend
	\begin{scope}[shift={(11,4)}] 
	\draw [blue] 
		plot[only marks, mark=*, mark options={fill=white}]  (0.25,0) -- (0.5,0) 
		node[right]{J30};

	\draw [red][yshift=\baselineskip]  
		plot[only marks,mark=triangle*, mark options={fill=white} ] (0.25,0) -- (0.5,0)
		node[right]{J60};

	\draw [green][yshift=2\baselineskip]  
		plot[only marks,mark=square*, mark options={fill=white}] (0.25,0) -- (0.5,0)
		node[right]{J90};

	\draw[yshift=3\baselineskip] 
		plot[only marks,mark=square*] (0.25,0) -- (0.5,0)
		node[right]{J120};

	\end{scope}
\end{tikzpicture}
\end{document}