According to the NYC Dept of City Planning: "MapPLUTO is freely available to all New York City agencies and the public."
The MapPLUTO dataset is produced by the NYC Department of City Planning. It contains individual tax lots (aka tax parcels) with a variety of attributes including zoning, land use, land value, building descriptors, and a number of administrative identifiers. These datasets were formerly copyrighted and use was restricted, but in 2013 the City lifted the license and is now freely providing the data. The datasets on this page are historical and were released in April 2008 (Release 07C.1). To access the most recent series visit the NYC Dept Planning Bytes of the Big Apple - PLUTO and MapPLUTO page.