Simple answer: NO.
There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit and the Child Tax Credit. They are interrelated but the rules are different for each.
They cannot be your QC because they do not live with you.
In order for them to be a qualifying relative, you would have to have provided more than half their total support. In addition, you brother must not be required to file a tax return. Just sending money to help is unlikely to meet this standard.
The IRS has a worksheet that
can be used to help with the support calculation. See: http://apps.irs.gov/app/vita/content/globalmedia/teacher/worksheet_for_determining_support_4012.pdf The support
value of the home your brother provides is the fair market rental value plus utilities, divided by the number of
occupants.
