Thanks to all. Dear one of our relative has applied for 173.They have a son of 23.5 years and his study is regular and currently doing masters in mechanical engineering, fully dependent on them and included him in application. Has they done the right thing to include him? They are really worrying about their son because their agent is not clearing the things about their son. If they are able to get the visa and after two years when they will apply for 143, is it required that their son has to continue his study during that period of 2years while living on 173 in order to get 143. Any one pls put some light on this.