In my opinion Etherium and Cardano will be the best choice for the next 3-6 months. You can invest into this coins for good returns. Also Neo is a good choice too.
ethereum is good for investment at any time, but cardano doesn't seem so good now. or you can try to see BNB and LTC, this is my investment choice, there is also EOS, but I speculate on the growth of EOS, because their platform is not so big this year. maybe for the long term.