Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
remission [rɪˈmɪʃən] n (cancelling, of debt, fee) освобожде́ние; (reduction, of prison sentence) сокраще́ние; (MED) реми́ссия; (REL) отпуще́ние
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.