Sec 194C - i ) if the car is in control of the person who provides the car on hire ie the driver is provided by the person who gives the car on hire.
ii) there is contract for some specific work between the car hiring company & the company or the person who provides the car on hire, either oral or written.
In all the above situations the nature of transactions comes in the scope of contract only.As the car hiring company has given some work to the person who provides the car on rent and to perform such work car is being used as a tool for the performance of work.
Sec 194 I - if the car is hired and it is in total control of the person hiring the car for the period for which the car is hired. Here the nature of transaction is that the car is taken on rent & it comes under the scope of "rent for Plant & machinery "and accordingly TDS will be deducted @ 10%
In your case TDS will be deducted under Sec 194C.