In this work, we developed a model for a non-volatile memory cell, based on the electrical model for TiOX/HfOx ReRAM cell and the hybrid electro-thermal model of VO2 Mott selector developed recently by our team. Both models are calibrated and validated with experimental data, and the operating characteristics of one-selector-one-ReRAM (1S1R) memory cell are studied. The length of the selector layer is varied as a design parameter to meet the design requirements for proper read, write and erase operations. Simulation results suggest that modified selector cell with 60 nm length of VO2 layer meets all the requirements for proper operations with the cell write voltage of 1.6 V and erase voltage of 2.5 V. The access time for this structure is studied by benchmarking with experimental data and is estimated to be less than 10.5 ns for write operating and less than 16ns for the erase operation.