Panel a: IRAC color-color plot for the sources in the H IIregions. The boxes demarcate the location of Class I (larger box)and Class II (smaller box) (Vig et al. 2007). Sources falling in the overlapping area are designated as Class I/II. The identified YSOs have the following color coding - Class I (red), Class II (green) and Class I/II (cyan). Panel b: histogram showing the number of sources within specified spectral index bins. The regions demarcated on the plot are adopted from Chavarría et al. (2008) for classification of YSOs.