On January 19, his pulse becomes irregular. When his doctor inquires whether they should prepare for cardiac resuscitation, Osho says, ‘No, just let me go. Existence decides its timing.’
He leaves his body at 5 p.m. See here for the transcript of his doctor’s message delivered in Buddha Hall describing Osho’s final moments, including Osho’s last words.
At 7 p.m. his body is brought to Gautama the Buddha Auditorium for a celebration, and is then carried to the burning ghats for cremation.

Two days later, his ashes are brought to Osho Commune International and placed in his samadhi in Chuang Tzu Auditorium with the inscription:

OSHO
Never Born
Never Died
Only Visited This Planet Earth Between
11 December 1931 – 19 January 1990