行かないんの？行くんじゃないんの？
 

I want to know the difference between 行かないの？and 行くんじゃないんの？and 行かないんじゃないの？

Thanks x 99999999999999

行かないの = Will you go? / You're not going? based on context
行くんじゃないんの = where the heck are you getting this from? it's not correct, but it almost sounds to me like Aren't you going? But it's wrong at the end.
行かないんじゃないの = Aren't you not going?

sorry that was a typo, it was supposed to be 行くんじゃないの

Out of curiosity, what level of Japanese are you in?

Are you saying the whole sentence is not correct, or are you just pointing out that the んの at the end is incorrect?

I just want to confirm because I'm a bit confused by your sentence, and surely 行くんじゃないの is correct as it is confirming the positive. :)

Sorry if I misunderstood.

Edit: I all of a sudden just understood what you are saying, ignore this post if you like :p

So I'm pretty sure because ん is a shortened の to begin with, you can't use them together like you have.

I'm pretty sure Kyle has summed it up for you, although 'Aren't you not going?' could be better put as 'You're not going right?'

んの？　Is it a dialect?

行かないんの？　　　　→　行かないの？
行くんじゃないんの？　→　行くんじゃないの？

To the best of my knowledge, it's not a dialect—it's just wrong.