[SueM]

Definitely not a Jack Russel. Except for coat color and the tail, it doesn't look like one. It appears to be a med/large breed puppy with a double coat. Except for the docked tail, it resembles an Akita puppy.

 

[SueM]

The thing is that this puppy has a very short tale and akita puppies doesn't. The other particular is its snout. As i said before maybe its a mix, it has a lot of common with akita puppy but theres a part left.
I really want to know what breed this dog is!

That's why I said "except for the tail"
You seem pretty determined to say this is a Jack Russel mix. It's too big for that. No matter what the breed/mix, it appears to be a puppy that will grow to be medium to large in size.