6. A Trustee elected under article 4(1)(a) shall, subject to articles 8 and 10 of, and paragraph 10 of Schedule 2 to this Order, hold office for the period of three years from 1st April next following his election and a Trustee appointed under article 4(1)(b) (other than a Trustee appointed under article 5(3)(a) shall, unless appointed to fill a casual vacancy and subject to articles 8 and 10 of, and paragraph 10 of Schedule 2 to this Order, hold office for the period of three years from 1st April next following his appointment.