From an advaitist standpoint, there are multiple, subjective realities, of inreasing homogeneity, experienced in different states of consciousness. There is a single, unified, objective, Real reality
Neither the sand, rope, water or snake are Real in expanded realities. There is only the experiencer experiencing itself.
At the time one's dreaming of them, though, from 2nd-state (REM) consciousness, they and the dreamer are all real; all part of the subjective, dualistic reality of the dreamer.
From the Ultimate, objective, Real Reality, though, all are unified into a single Unity.