What happens after attaining Nirvana?

According to Osho, after nirvana the mind dissolves into emptiness, yet a subtlest trace of being and the living body remain. The enlightened one may still move among people—Buddha, out of compassion—until death. With the body's dissolution comes mahanirvana: sovereign, supreme emptiness beyond perception. In Krishna, nirvana and mahanirvana coincide; in Buddha they are sequential.

Waking up ends the noisy mind, but the body keeps going; some enlightened ones keep helping kindly until death, when everything rests in total peace.