Risani maf hosh Birbhadra for bringing all those ethnicity on this thread. They used to select from, as you said, certain ethnic groups because of their guru pujari eklabya character, but few years onwards, all ethnic groups are welcome on applying as a gurkha (or better say gorkhali). Now you can meet mahendra shah, girija nepal, madhav koirala, pashupati shrestha, balabhadra kunwara and all the jhilkays of as you said certain ethnic groups. Hoina ta Lahure dai?