There are definitely a number a self guided tracks close to the Ruapehu Mountain Motel and Lodge. For example:
The Mangaturuturu Valley Hut and Lake Surprise - this is a fantastic one day walk that has wonderful views of Mt Ruapehu, cascading waterfalls, a picturesque river valley at the base of the mountain and a hidden tarn. One of the best one day walks in NZ!
Waitonga Falls, Blyth Hut and /or Mangaehuehu Hut - a lovely walk with waterfall, mountain streams, native bush and superb views of Mt Ruapehu.
The Old Coach Road - Walk or bike this track that starts just 200m from the Ruapehu Motel and Lodge. With a historic renovated viaduct, native bush, and tunnel to explore this track is suitable for all the family.
Hope this helps