latex two column layout set figure to load on single column

use the environment center instead of figure. Of course you have to use \captionof{figure}{<text>} or with the package caption \captionsetup{type=figure}.

multicols uses saveboxes to split the contents. In this case you can't use any floating material.

Example with center, captionof and captionsetup: FYI: captionof requires the package caption or capt-of or a documentclass of the KOMA Bundle; captionsetup requires the package caption.

\documentclass[english,demo]{scrreprt}
\usepackage{babel}
\usepackage{blindtext}
\usepackage{multicol}
\usepackage{graphicx}
\usepackage{caption}
\begin{document}
\blindtext
\begin{multicols}{2}
\blindtext
\begin{center}
  \includegraphics[height=60mm]{CC.jpg}
  \captionof{figure}{AA \cite{BB}}
\end{center}
\blindtext[2]
\end{multicols}
\blindtext
\clearpage
\blindtext
\begin{multicols}{2}
\blindtext
\begin{center}
\captionsetup{type=figure}
  \includegraphics[height=60mm]{CC.jpg}
  \caption{AA \cite{BB}}
\end{center}
\blindtext[2]
\end{multicols}
\blindtext
\begin{thebibliography}{99}
\bibitem{BB} Name, Title
\end{thebibliography}
\end{document}

the figure environment don't work inside the multicol environment. You have to choose the \twocolumn command or alternatively the package caption and then

\begin{multicols}{2}

\begin{center}
  \includegraphics[height=60mm]{CC.jpg}
  \captionof{figure}{AA \cite{BB}}
\end{center}

\end{multicols}

However, if you want the image span both columns, then you have to split the multicol environment:

\begin{multicols}{2}
foo
\end{multicols}

\begin{figure}[!ht]
  \centering    
  \includegraphics[height=60mm]{CC.jpg}
  \caption{AA \cite{BB}}
\end{figure}

\begin{multicols}{2}
bar
\end{multicols}