I'd recommend buying new from Toyota - they are cheap. There are 4 total brackets (2 in each side) and if you are doing it, I'd recommend new bolts and bushings too.
16583-61030 - radiator to core support No 1. (passenger)
16582-61030 - radiator to core support No. 2 (driver)
16585-61020 - direct to radiator (left and right)