Is it permissible to duchan during a mourning year – after Sh’loshim – after a parent has died?
There are different minhagim regarding a cohen duchining during the aveilus year. In Eretz Yisroel where the cohanim duchin evey day, the cohanim duchin even during the shloshim. However in Chutz La’aretz the Ashkenazi minhag is to follow the Rama, and not to duchin the whole year, unless there isn’t another cohen there to duchin. The Sephardi minhag however is do duchin even during the avielus year, as long as it is after shiva.
O”H 128-43, M”B 159 , Kitzos Hashulchan23-23.