I was power of attoeny for my bro.he was in nursing home but i paid out $1000. even tho he passed way in aug. can i claim him his address was my address his death certif

Your brother can be your tax dependent if he earned less than  $4050 of taxable income and if you paid more than half his overall living expenses.  If more than half his expenses were paid by his funds, or by medicaid, or other government programs, then he is not your tax dependent even though you also supported him.