(a) For the purpose of carrying out its duties and effectuating the decisions of the department of youth services with respect to the classification, placement for training and treatment, transfer, release under supervision and discharge of persons committed to the department the commissioner of youth services is authorized to make use of law enforcement, detention, supervisory, medical, educational, correctional, segregative, and other facilities, institutions and agencies, whether public or private, within the commonwealth wherever feasible, otherwise outside the commonwealth; provided however, that the department shall not transfer custody of any person who was committed to the department by a juvenile court or district court juvenile session and who is under eighteen to a penal institution. The commissioner of youth services may enter into agreements with the appropriate private or public officials for separate care and special treatment in existing institutions of persons committed to the department. In cases where a person has been adjudicated a delinquent for a violation of section one of chapter two hundred and sixty-five, the commissioner of youth services may, with the concurrence of the commissioner of correction, transfer the custody of said child to the department of correction, provided that such person has reached his eighteenth birthday. At least twice annually, the commissioner of youth services with the assistance of the executive secretary to the advisory committee shall be responsible for convening and programming a meeting of a youth services coordinating council composed of the commissioners of public health, mental health, education, transitional assistance, corrections, and probation, and the commissioner of administration and finance or their designees. The youth services coordinating council shall meet for the purposes of providing for the coordination and mutual assistance in the carrying out and evaluation of all the programs relating to youth services in the commonwealth. Said council shall jointly prescribe and from time to time amend rules and recommendations of their various departments for the aforementioned purposes.