Is rescale a word in the Scrabble Dictionary

Yes, rescale is playable

...and is worth 11 points.

Found in the following dictionaries

Enable (Words with friends)
SOWPODS (Collins Scrabble Words)
OTCWL2014 (NASPA Word List 2014)
TWL06 (NASPA List 2006)

"Rescale" Definition

verb

To alter the scale of a drawing or project; to change the physical proportions.
Source: Wiktionary
To change the scope of a business or project to meet a change in demands.
Source: Wiktionary
To plan, establish, or formulate on a new and usually smaller scale.