THE ALL-FATHER: At the beginning of your turn, choose a standard attack power. Odin and friendly characters 150 points or less can use that power this turn.

If you choose a ranged attack power, and it is given to a clix on your team with 0 range, does their range stay 0, or is there a minimum they get to use?

It doesn't specify otherwise, and there's no reason they would get a + to range, so it remains 0.

Unless the power is one that grants a minimum range (which as far as attack powers go, is just Smoke Cloud), their range would remain 0.