I am a BTC holder. Some People said BTC is going down to $1000!! Is it true? So what can i do sell all BTC or hold it anyone know?

These are all speculatives prices and shouldn't be taken seriously as many have fall prey to these type of fud. Asking if the price if Bitcoin will crash to $1000 is a typical imagination that's unrealistic because many have now known and have been aware of the positive impact of cryptocurrency and Bitcoin being the mainstream.
Bitcoin is a game of gains or losses but this depends on the individual that's involved. At one time I lose to the system and at the other end I gain or win. These things can be seem in individuals base on their skills, either as a trader or an investor.