Hey, Your brother need not be disturbed or depressed however certainly seems confused about marriage and his expectations of life partner. I can imagine what your family might be going through balancing between your responsibility, love & concern on one hand and his seemingly ignorant & confused take on marriage on the other. What is required from your brother's end is a certain clarity about his views on marriage, expectations from the partner, idea about the relationship and the sort of role his family is expected to play during the process. Only when he is clear and firm, can you gain a clarity about process of engaging his marriage. Please take an assistance of a psychologist or counselor who could help your brother gain clarity and also to express his point of view freely.