  We present a detailed analysis of the photometric properties of galaxies in
the cluster \A2163B at redshift z~0.2. R-, I- and K-band structural parameters,
(half light radius r_e, mean surface brightness <mi>_e within r_e and Sersic
index n) are derived for N~60 galaxies, and are used to study their internal
colour gradients. For the first time, we use the slopes of optical-NIR Kormendy
relations to study colour gradients as a function of galaxy size, and we derive
the Photometric Plane at z~0.2 in the K band. Colour gradients are negligible
at optical wavelengths, and are negative in the optical-NIR, implying a
metallicity gradient in galaxies of ~0.2 dex per radial decade. The analysis of
the Kormendy relation suggests that its slope increases from the optical to the
NIR, implying that colour gradients do not vary or even do become less steep in
more massive galaxies. Such a result is not simply accomodated within a
monolithic collapse scenario, while it can be well understood within a
hierarchical merging framework. Finally, we derive the first NIR Photometric
Plane at z~0.2, accounting for both the correlations on the measurement
uncertainties and the selection effects. The Photometric Plane at z~0.2 is
consistent with that at z~0, with an intrinsic scatter significantly smaller
than the Kormendy relation but larger than the Fundamental Plane.
