A State Supreme Court justice granted the request for a hearing by a group of plaintiffs who say Governor Cuomo pushed the law through by suspending the three-day review usually required.
The bill, which was passed on January 15, was put to an immediate vote by Cuomo, who issued a "message of necessity".
A spokesman for the governor said they believe the process was valid and constitutional.
New York was the first state in the country to toughen its gun laws after the Newtown, Connecticut school massacre.
The bill limits magazine size and cracking down on assault weapons.
A court date is set for March 11.