To fully answer this question, I would need to know what model Nissan, but there are a few common areas. Just inside the driver side door, look above the brake pedal, or on the side panel to the left of the brake pedal. If not there, then it could be in a black case, next to your battery.
I need more info to say exactly where. In most cars it will be located inside, under the dash on the driver's side kick panel. Or possibly under the hood.
fuse boxes in most cars are in a few spots. either in the engine compartment on the left or right side towards the back. under the dash by the drivers knees. or on the drivers side infront of your left knee on the outside of the dash inbetween it and the door
The Maxima, Altima, Sentra, and 240sx models have the fuse box located in the passenger compartment. On the drivers side, either behind an access panel or in a separate fuse box on the kick panel. There is also a fuse and relay sensor under the hood in the engine compartment.
Located in the passenger compartment near steerling wheel. Pull panel to see
the fuse box. Look for the fuse boxes,located both in your engine compartment and under the dashboard in a Nissan Altima.