% Please add the following required packages to your document preamble:
% \usepackage{multirow}
% \usepackage[table,xcdraw]{xcolor}
% If you use beamer only pass "xcolor=table" option, i.e. \documentclass[xcolor=table]{beamer}
\begin{table}[]
\begin{tabular}{|l|l|l|l|l|l|}
\hline
\multicolumn{1}{|c|}{}                                 & \multicolumn{1}{c|}{}                                & \multicolumn{1}{c|}{}                                         & \multicolumn{3}{c|}{\textbf{Availability}}                                     \\ \cline{4-6}
\multicolumn{1}{|c|}{\multirow{-2}{*}{\textbf{Class}}} & \multicolumn{1}{c|}{\multirow{-2}{*}{\textbf{Tool}}} & \multicolumn{1}{c|}{\multirow{-2}{*}{\textbf{Approach type}}} & \textbf{Documentation}   & \textbf{Source Code}     & \textbf{Executable}      \\ \hline
                                                       & ATAC                                                 & Coverage-Based                                                & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} \\
                                                       & Rostra                                               & Coverage-Based                                                & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} \\
                                                       & Raspect                                              & Coverage-Based                                                & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} \\
                                                       & RUTE-J                                               & Coverage-Based                                                & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} \\
                                                       & Randoop                                              & Coverage-Based                                                & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} \\
                                                       & GenRed                                               & Coverage-Based                                                & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} \\
                                                       & Jtop                                                 & -                                                             & {\color[HTML]{009901} ✓} & {\color[HTML]{CB0000} X} & {\color[HTML]{009901} ✓} \\
                                                       & TOBIAS                                               & Coverage-Based                                                & {\color[HTML]{009901} ✓} & {\color[HTML]{CB0000} X} & {\color[HTML]{009901} ✓} \\
                                                       & TEMSA                                                & Search-based                                                  & {\color[HTML]{009901} ✓} & {\color[HTML]{CB0000} X} & {\color[HTML]{009901} ✓} \\
\multirow{-10}{*}{Randomized Unit-Testing}             & Open-SourceRed                                       & Coverage/Search-Based                                         & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} \\ \hline
                                                       & USbRed                                               & Similarity-Based                                              & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} & {\color[HTML]{CB0000} X} \\
\multirow{-2}{*}{User session testing}                 & CPUT                                                 & Coverage-Based                                                & -                        & -                        & -                        \\ \hline
                                                       & RTL                                                  & Coverage-Based                                                & -                        & -                        & -                        \\
\multirow{-2}{*}{Retargeted compilers testing}         & PLOOSE                                               & Coverage-Based                                                & -                        & -                        & -                        \\ \hline
                                                       & MINTS                                                & ILP-Based                                                     & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} \\
\multirow{-2}{*}{Integer linear programming}           & EDTSO                                                & ILP-Based                                                     & -                        & -                        & -                        \\ \hline
                                                       & SrTC                                                 & Coverage-Based                                                & -                        & -                        & -                        \\
                                                       & JINSI                                                & Coverage-Based                                                & -                        & -                        & -                        \\
\multirow{-3}{*}{Automated fault-localization}         & Gzoltar                                              & Coverage-Based                                                & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} & {\color[HTML]{009901} ✓} \\ \hline
\end{tabular}
\end{table}