Where can I find the deductible fee on my registration paper for my car?

Depends on what state you are in. Your DMV can help you with that. 

You can’t deduct the total amount you paid, only the portion of the fee that’s based on your vehicle’s value can be deductible when you itemize your deductions. 

However, as Bosch477 mentioned it depends on what state you are in. Not all states have value-based registration fees. Refer to the following link for information related to your specific situation:

Is my car registration fee deductible?

To report the deductible amount check : Where do I enter my car registration fees?