  Red giants are an excellent tool for probing the history of star formation
and subsequent metallicity evolution in the galaxies. The well-defined red
giant branch (RGB) stars of the globular clusters can be used to determine
their slopes and to calibrate the RGB slope parameters, age, and metallicity
relations. We obtained deep near-IR $JHK$ stellar photometry of 23 LMC/SMC
globular clusters. The cluster sample covers a wide range in metallicities
$(-1.76<{\rm [Fe/H]}<-0.32)$ and ages $(0.6\,{\rm Gyr}<t<14\,{\rm Gyr})$. The
slope of the RGBs of each cluster was calculated and used to derive the
relations between slope-age-metallicity. We have found that the RGB slope do
not shows any statistically significant age dependence. The young and old
clusters are found to be distributed differently in RGB slope-metallicity
space, and the younger populations show a slightly less steep RGB slope
dependence than the whole cluster sample. The population of the younger
clusters shows a negative slope, whereas the older clusters show a positive
slope.
