It is said that when our solar system passes through the dark rift of galaxy (what is it exactly?), a phenomenon named 'Galactic Eclipse' happens, when our solar system witnesses 3 days of darkness. Is it possible even in this case that there would be no light in the night sky, as there are many stars in the night sky. (don't consider city lights and other artificial human interference)
Definitely a hoax as other commenters have said.
Dark rifts exist in the galaxy - large clouds of dust, several can be made out by eye, overlapping the milky way, in ideal conditions. See for example the Great Rift. However these are so large it would take far longer than three days for a solar system to pass through them. Probably thousands or millions of years. So this is definitely incorrect information.