From eight actions to two
Ancient Indian theory named many hand actions. This is history — not the modern hand map, and never a demonstration.
Bharata's named actions
Bharata's Nāṭyaśāstra describes four audible and four silent hand actions used to mark musical time. A modern North Indian tabla treatise states plainly that these actions do not survive in their ancient form in Hindustani practice.
D1, 2
Not one fixed list
Pārśvadeva's Saṅgītasamayasāra preserves a Bharata-related group and then names a separate set of eight actions of its own — evidence that historical writers did not all keep one identical vocabulary.
C3
What can honestly be said
Ancient theory distinguished sounded and unsounded time-marking; modern Hindustani practice also distinguishes them. But the descent from any single named ancient action to a specific modern gesture is unproven — a physical resemblance is not a lineage. Teach the eight as history, not as a hand map to imitate.