Correct increasing order for the wavelengths of absorption in the visible region for the complexes of ${\mathrm{Co}}^{3+}$is

The order of the ligand in the spectrochemical series ${\mathrm{H}}_2\mathrm{O}<{\mathrm{NH}}_3<\mathrm{en}$
Thus, the wavelength absorbed will be in the opposite order i.e., 
${\left[\mathrm{Co}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}>{\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]}^{3+}>{\left[\mathrm{Co}{\left(\mathrm{en}\right)}_3\right]}^{3+}$

$\mathrm{wave} \mathrm{length} \mathrm{of} \mathrm{light} \mathrm{absorbed} \infty \frac{1}{\mathrm{strength} \mathrm{of} \mathrm{ligand}}$