Let's see
[tex]\\ \sf\longmapsto F=G\dfrac{Mm}{r^2}[/tex]
[tex]\\ \sf\longmapsto G=\dfrac{Fr^2}{Mm}[/tex]
[tex]\\ \sf\longmapsto G=\dfrac{Fr^2}{m^2}[/tex]
[tex]\\ \sf\longmapsto G=\dfrac{Nm^2}{kg^2}[/tex]