Is 6 years a light sentence for this crime & does may be deported back to Mexico mean he could get amnesty?

This is why I have an issue with the word "Undoented" .. See he will serve 80% of his sentence and then he is eligible for deportation. Dude is going to get sent home, sneak back in under a different name and poof..... He will be eligible for a mail in Amnesty...