I just updated from Kde4 to Plasma, and found that all the Indic keyboard layouts (such as Punjabi or Hindi) are missing from the keyboard system settings module. There was a time that these layouts had been removed from the xkb system for some reason - does plasma have its own copy of xkb, and is it out-of-date? Any way to put the indic layouts back in?
I found the layouts, so this is just user error. Leave the language box on 'Any Language', choose 'Indian' as the layout, and the Indic languages are, in fact, there. Perhaps there is a usability issue here, in that these languages should be added to the 'Limit Selection by language' list, so they can be more easily discovered. Marking as resolved, not-a-bug.