After you file

If you claimed your brother as a dependent then you do NOT put his unemployment on your return.   However if he is over the age of 18  and  his unemployment was more than $4300 you cannot claim him as a dependent.

You may need to amend for that reason.

 

If he had withholding on the 1099-G and/or he got more than $12,400 then he needs to file his own return.