DISCLAIMER: Math everywhere ahead, you have been warned.
Before I begin:
Just saying, but a level 1 Oshawott will almost always have 12 HP / 6 in other stats. That's because it's,
- HP, Attack and Special Attack are always 12 / 6, even if you have like 0 IVs in all three
- Defense, Special Defense and Speed would be 6 for an IV range of 10-31
So there's no way to say that it's perfect, unless you confirm with the IV judge.
Now to the ideal answer:
No it is impossible. 3 IVs are passed down from the parents, and I believe that neither of them has a perfect IV that can pass down. Even if your Oshawott miraculously has 3 perfect IVs, the other 3 will be the inherited bad IVs.
However, assuming that 3 perfect IVs are passed down,
Chance of getting 31 IVs in one stat = 1/32
Therefore, chance of getting 31 IVs in three stats
= 1/32 1/ 32 1/32
= 0.003% approximately
It's still hilariously low. Take the hint, and avoid this stunt. There are far better ways to get a 6 IV without cracking your head over that chance.
Hope I helped!