You can also just do it manually by going to www.whattomine.com and selecting your GPU and it will tell you which coin is most profitable. Most likely there won't be any benefit to switching coins, usually ETH is currently most profitable and will be a while before something else has a higher profitability.
If you got RX series video cards just mine ETH or ETC. There is nothing else out there that is going to make you more money. Currently mining is overall not very profitable.
Yes but Nicehash support only BTC/Dash right now or no ? I want software which choose best mineable and profitable ALTcoins for my GPU"s (nvidia for now)
In whattomine.com, you will see what coins that will be profitable to mine if you use your GPU. You can check how much reward that you can get using the GPU. I guess Nicehash supports many coins to mine, and it will suggest you the profitable coins to mine.
The image below is an example of how much hashrate you will get from your GPU:
You can see the green on that image is the type of GPU. You can choose the type of your GPU, don't forget to click the right like what I did.
After you know what the coin that can be profitable with your GPU is, you can search on the pool that supports for receiving the payment for the coins. For example, if you want to get payment in Dash, you should seek the pool website to start mining, or you can try with https://miningpoolhub.com/.
You can download the software from that site that will match with your GPU.