Yes, he can.
As mentioned in this FAQ (https://riadmissions.freshdesk.com/a/solutions/articles/51000176705), we are looking for students with exemplary character and outstanding personal qualities as seen through their behaviour and actions.
Being in a leadership position alone is not what we are looking for. What is more important is how his character / personal qualities have benefitted others through his position.
This also means that even if a student is not holding a leadership position, but can show evidence in other ways, he can still be considered for the Leadership & Character DSA.
This is why, in addition to the student's primary school records, we ask students to submit a personal statement (more information here).