It's directional
All seven planets must fall on the same side of the Rahu–Ketu axis — not just near it.
When Rahu and Ketu hem in everything
Kaal Sarp Dosha occurs when all seven classical planets (Sun through Saturn) fall on one side of the Rahu–Ketu axis — hemmed in like a snake coiling around them.
How to check
Generate your free Kundali and check the planetary positions table — if every other planet's house falls between Rahu and Ketu going the same direction around the chart, that's the classic Kaal Sarp pattern.
All seven planets must fall on the same side of the Rahu–Ketu axis — not just near it.
If even one planet falls on the other side, it's generally not considered a full Kaal Sarp Dosha.
Which house Rahu occupies determines the specific type and its traditional emphasis.
Reference