Fed-up Forest Hills residents are taking their battle against the neighborhood’s namesake concert hall to a new level — suing the NYPD over what they claim is an illegal takeover of private streets, The Post has learned.

A whopping 63 speakers signed up to take the mic at Community Board 6’s meeting last Wednesday, mostly to weigh in on the future of concerts at Forest Hills Stadium. The packed hearing came on the heels of a March 19 letter from Inspector William Gallagher of the NYPD’s Legal Bureau stating that the agency could not grant the necessary permits to hold events at the venue. The Forest Hills Gardens Corp., which owns the surrounding private streets, has denied the city access t