Yes. Or more accurately you may use what you pay him, up to $6000 (2 or more kids), to calculate the dependent care credit.  You will have to provide his SS# on the tax form ( form 2441).  This assumes your brother is not your dependent.

Does he have to report the income  and pay tax? Technically yes, there is no age limit in the U.S. income tax system.  If he babysits in his home, he is considered self employed and has to file if he has more than $400 of income for the year. He will not owe any income tax, but he will  have to pay FICA (social security and medicare) tax in the form of self employment tax (SET).  If he watches the kids  in your home, he is considered a household employee. Household employees under 18 are exempt from FICA. A household employee with less than $12,200 of income does not need to file.  

If I understand you, you are asking if you can claim the Dependent Care Credit for the money you paid your brother to babysit your kids.  

The answer is Yes, you can.  To enter information in the TurboTax online, here are the steps:

• Sign in to your account, select Pick up where you left off
• At the right upper corner, search for child care credit, then select  "Jump to" link
• Follow prompts

If your brother babysat in your house, technically he is considered as a household employee.  However, since he meets one of the exceptions, you might not need to file Schedule H. See https://www.irs.gov/pub/irs-pdf/i1040sh.pdf, page H-4.  To verify if you need to file the Schedule H in the program, click here: How to enter schedule H

If he babysat at his place, he is considered self-employed and must pay social security and medicare tax in the form of self-employment tax by filing his own taxes. 

For more information about the household employees, click here https://www.irs.gov/instructions/i1040sh, under "Did you have a household employee?"

@christa5013