Different nations, the Métis or the Inuit may have different views of terminology, but one of the difficulties, as suggested by Phil Goulais, is that “restitution” sounds like a recognition that all of the sovereignty and rights are with the Crown, and that the Crown then gives lands back or renounces what the Crown had. Many first nations, in my experience, start from a proposition that there wasn't a fair dealing in the past or a renunciation or surrender or ceding of rights.
In terms of a different terminology, there are other terms, like “reconciliation” or “addressing the lands question in Canada”, but I think there needs to be a bit of flexibility depending on the particular first nations, Inuit or Métis in Canada.