N.Y. Real Prop. Tax Law § 1206

§ 1206. Complaints. If any city, town, village, special assessing\nunit, or approved assessing unit or eligible non-assessing unit village\nwhich has adopted the provisions of section nineteen hundred three of\nthis chapter proposes to complain at the hearing of the commissioner\nconcerning the tentative equalization rate, class ratios and class\nequalization rates determined for it or any portion contained therein,\nsuch city, town, village, special assessing unit, or approved assessing\nunit or eligible non-assessing unit village which has adopted the\nprovisions of section nineteen hundred three of this chapter must cause\na written complaint specifying its objections to be served on the\ncommissioner at least five days before the day specified for the\nhearing. Service may be made either in person or by mail. A complaint\nconcerning data used for purposes of a tentative equalization rate,\nclass ratio, class equalization rate or special equalization ratio shall\nbe deemed a complaint with respect to such data for all such purposes.\n