documentclass[twocolumn,trackchanges]{aastex61}

usepackage{natbib}
usepackage{graphicx}
usepackage{latexsym}
usepackage{amssymb}
usepackage{longtable}
usepackage{rotating}

begin{document}

title{Here is the title}

section{this is main section} label{Section 1}
subsection{this is subsection} label{Section 1.1}
There are some paragraphs in here.

newlength{imageheight}
setlengthimageheight{dimexprtextwidth-abovecaptionskip}
begin{sidewaysfigure}
        includegraphics[height=1textheight,width=1textwidth]{m12b_low_low}
    caption{This is some caption}
    label{fig:Figure 1}
end{sidewaysfigure}


end{document}