\documentclass[a4paper,12pt]{report}

\usepackage[inner=0.75in,outer=0.65in,top=0.75in,bottom=0.75in]{geometry}

\usepackage[sc]{mathpazo}

\usepackage{multirow}

\begin{document}

\begin{table}[!htb]

  \centering

  \caption{Present Strength-Production}

  \begin{tabular}{|c|l|l|c|c|c|c|c|c|}

    \hline

    \multirow{2}{*}{Sl.No} &

    \multicolumn{2}{c|}{\multirow{2}{*}{\textbf{Designation}}} &

    \multicolumn{4}{c|}{\textbf{Shifts}} & \textbf{Leave/Off} &

    \multirow{2}{*}{\textbf{Total}} \\

    \cline{4-7}

    & \multicolumn{2}{c|}{} & \textbf{A} & \textbf{B} & \textbf{C} & \textbf{G} & \textbf{Reserve} & \\

    \hline

    1 & \multicolumn{2}{l|}{Plant Engineer} & & & & 1 & & 1 \\

    \hline

    \multicolumn{1}{|l}{} & \multicolumn{2}{l|}{\textbf{Sub Total}} & & & & \textbf{1} & & \textbf{1} \\

    \hline

    2 & \multirow{2}{*}{Operator}&Work related to water regeneration & 1 & 1 & 1 & & 1 & 4 \\

    \cline{1-1}\cline{3-9}

    3 & & Work related to valve control & 1 & 1 & 1 & & 1 & 4 \\

    \hline

    \multicolumn{1}{|l}{} & \multicolumn{2}{l|}{\textbf{Sub Total}} & \textbf{2} & \textbf{2} & \textbf{2} & & \textbf{2} & \textbf{8} \\

    \hline

    1 & \multicolumn{2}{l|}{Worker} & 2 & 2 & 2 & & 2 & 8 \\

    \hline

    \multicolumn{1}{|l}{} & \multicolumn{2}{l|}{\textbf{Sub Total}} & \textbf{2} & \textbf{2} & \textbf{2} & & \textbf{2} & \textbf{8} \\

    \hline \hline

    \multicolumn{1}{|l}{} & \multicolumn{2}{l|}{\textbf{Total}} & \textbf{4} & \textbf{4} & \textbf{4}

    & \textbf{1} & \textbf{4} & \textbf{17} \\

    \hline

  \end{tabular}

  \label{tab:pro_pro}

\end{table}

\end{document}