N.Y. Real Prop. Acts. Law § 1513
If it shall appear by the complaint or is otherwise made to appear to the court at any time before a final judgment, that a defendant is or might be an infant, or incompetent to manage himself or his affairs, or that a future interest in the affected real property has been so limited that as yet there are neither certain nor presumptive owners thereof in being or ascertained, such court shall appoint a guardian ad litem who shall represent and protect such infant or incompetent, or the possible interests of the person or persons who eventually may become entitled to such real property or to an interest therein under such limitation, and in case of the death or failure or inability of such guardian to act, a successor, who shall appear for such infant or incompetent or for such possible interests until the termination of such action.
N.Y. Real Prop. Acts. Law § 1513