Here are copies of the ILS Approaches to both Runways 22 at KJFK.
As a rule of thumb, ATC will vector and descend arrivals so as to be level and slightly below the glideslope (the radio beam that controls the arrival vertically). ATC’s goal is to help the flightcrew first intercept the localizer (the radio beam that aligns the arrival laterally) before crossing the Final Approach Fix (FAF), thus positioning them so they can then intercept and proceed to ‘join’ the glideslope. The FAF on these approach plates show glideslope intercepts at 1,900 and 1,800 feet (see the profile views on the lower part of each approach plate); notably, these altitudes define the lowest altitudes ATC can assign and still legally issue an ILS clearance. Note, also, on both profile views, the glideslopes are declared at the standard 3.00°, which in rough terms translates to a descent of 300-feet per mile on final.