Some time ago I was reading a friend's paper and it noted a seal which had been uncovered from a Harappan site (Indus Valley Civilization). Some suggest it is a "yogic posture". If that's true it means there were yogic traditions in India stretching back to Harappan times.
The figure could have been portrayed simply at sitting, but this is unclear.
It would confirm the Jain and Buddhist ideas of yogis being around the subcontinent for innumerable years prior to Mahavira and the Buddha.