\documentclass[a4paper]{oblivoir}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usepackage{tikz-3dplot}
\usetikzlibrary{shapes, calc, arrows, angles, patterns, quotes, fit}
\newcommand{\tikzmark}[2]{\tikz[overlay,remember picture,
    baseline=(#1.base)] \node (#1) {#2};}
\newcommand{\Highlight}[3][submatrix]{%
    \tikz[overlay, remember picture]{
        \node[highlight,fit=(#2.north west) (#3.south east)] (#1) {};}
}

\begin{document} 
     
    \tikzset{% 
        highlight/.style={rectangle,rounded corners,fill=ForestGreen!15,draw=ForestGreen, 
            fill opacity=0.3,thick,inner sep=0pt} 
    } 
    \[ \left[\begin{array}{c c c c c} 
    \tikzmark{a1}{1} & \tikzmark{b1}{1} & 3 & \tikzmark{c1}{1} & 6 \\ 
    2 & -1 & 0 & 1 & -1 \\ 
    -3 & 2 & 1 & -2 & 1 \\ 
    \tikzmark{a2}{4} & \tikzmark{b2}{1} & 6 & \tikzmark{c2}{1} & 3 \end{array}\right]    \Highlight{a1}{a2} \Highlight{b1}{b2}\Highlight{c1}{c2}\] 
\end{document}

혹시 tikz가 아니더라도 좋은 해결책이 있으면 알려주세요 ㅠㅜㅜ