Dont mine nxs direct to bittrex account it wont work.
I need to send it to my wallet to bittrex wallet, right?
Ok, I create a NXS and BTC wallet there, I select autosell for NXS, it will put it on the BTC wallet, and when I have enough I withdraw BTC on my bitcoin account that is outside of bittrex. Does I understand all?
Yes. If you're pool mining, it needs to go to your wallet first, and then to bittrex. If you're solo mining, it will be in your wallet automatically, so you can just send them to the exchange from there.
The only thing to know about autosell is that it dumps onto any waiting buy orders. It's good for speed, but it means you don't necessarily get the best price. (It's good for those of us trying to acquire more nxs cheaply, of course. Patience is rewarded, and impatience costs you a little bit. :-). But from a mining perspective, it's nice because everything becomes fully automated.