In the same as in which you received it. It should be functional in all respects, including air conditioning and audio system, and clean inside and outside. Remember that the inspection for compliance with the existing damages by what was recorded in the act when you were provided with a vehicle cannot be done until the car is washed. And, this is not only your money, but your time.
If the fuel level in the tank is less than what was at the time of receiving the car for use, no worries. The difference will be paid from the deposit.