please suggest me some best altcoins that can easily give 2x profit if I hold them 1-year.
There is no coin which can give you guaranteed returns.
Exactly! if it's just easy to predict a coin to give you 2x profit after holding it for 1 year then all of us here should rich by now. OP is missing the point that the market is unpredictable although anyone can suggest a coin but there is no assurance if that coin will increase it's price since the market is so volatile that anything can happen.