In this article, a Heterogeneous Gate-Dielectric Nanosheet Tunnel Field Effect Transistor (HD-NSH-TFET) with three channels is investigated using the 3-D Visual TCAD simulator. The HD layer of the proposed TFET consists of a high-k (HfO 2 ) placed over the extended source and channel interface and a low-k (SiO 2 ) at the extended drain and channel interface. An extensive comparison is outlined between the performance metrics of HD-NSH-TFET, conventional gate stack (GS)-NSH-TFET and negative capacitance nanosheet TFET(NC-NSH-TFET) configurations. The HD transistor exhibits an incredible leakage current of order 1e-18 A, while the gate stack demonstrates a leakage current of order 1e-16 A. The HD-NSH-TFET architecture ameliorates subthreshold swing (SS) and DIBL by 41.90 and 43.87 percent, respectively, over the GS structure. The HD-NSH-TFET device achieves a significant Ion/Ioff ratio (5.5e + 13), as well as an optimal subthreshold swing (13.88 mv/decade), while consuming minimal power and retaining excellent switching drivability. The effect of work function and oxide length on HD-NSH-TFET is investigated. The impact of temperature on DC and analogue parameters has been evaluated to ensure the device's reliability.