What does it mean?
The inspection found a tyre with inadequate tread depth, damage or unusual wear. The exact issue should be identified from the inspection report.
What should I ask a workshop?
Ask a tyre professional which tyre is affected and whether irregular wear calls for a suspension or alignment check.
Safety note
Severely worn or damaged tyres can make driving dangerous.
What about re-inspection?
In Finland, re-inspection is generally required within one month of a failed inspection if you want the defects reviewed without repeating the entire inspection. This does not establish driving permission. Check the actual decision and current official requirements.