Yes, REMITTAL is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, M 3, I 1, T 1, T 1, A 1, L 1.

Is it a valid word?

REMITTAL is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a payment of money sent to a person in another place
an abatement in intensity or degree (as in the manifestations of a disease)
the act of absolving or remitting; formal redemption as pronounced by a priest in the sacrament of penance

Also: remission of sin.