Roboinst has two working "modes"
- Do a install from PROM
- Do additional install from IRIX.
Only the second mode requires a license.
So you do not need a license for roboinst as long as you do them from PROM
Techpubs has a chapter on it in "IRIX Admin: Software Installation and Licensing," chapter nine, html version here:
Also in pdf form:
Copywrite 2000, not sure how current that is, I think these are the most recent release notes:
This from forum topic: here