http://tvline.com/2016/04/05/grimm-renewed-season-6-nbc/

In announcing the pickup, NBC Entertainment president Jennifer Salke said: “We absolutely love what our producers and cast have accomplished over the past five seasons."

http://tvline.com/2016/04/22/grimm-season-6-reduced-13-episodes/

The 22-episode season has been trimmed to 13 episodes.