In Jain Dharma, there is nothing above a Siddha.

A Siddha is a liberated soul that has gone to the top of the Lok and resides at Siddhashila. Beyond Siddhashila, there is no place, no body, no movement, and no world. So in Jain cosmology, Siddhas are at the highest possible state.

In simple words:

• Siddha = completely liberated soul
• Siddhashila = the highest point of the universe
• Above Siddha = nothing

If you meant “Siddha” and not “sidha”, this is the Jain meaning.