Hi there i have solved the issue by changing motherboard to the brand new motherboard.
I have been trying to play games like apex legends, rainbow six siege, csgo and others different game the GPU usage was so low like even 6% while i playing with these game and sometime hard frame rates drop. While playing the game with max settings the GPU utilization worked out normally like 100%. I have tried to put all of the settings to high performance including using G MODE but it have no changed at all. All of my driver had updated to the newest including window, nvidia driver ,dell bios settings 1.5 ver. Spec:
Dell G15 (intel edition) running low gpu process while gaming with lowest 
settings