Yes, REDEVELOPED is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, D 2, E 1, V 4, E 1, L 1, O 1, P 3, E 1, D 2.

Is it a valid word?

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

develop for a second time, in order to improve the contrast, colour, etc., of a negative or print
formulate or develop again, of an improved theory or hypothesis
change the plans for the use of (land)