This type of interference is spelled out in the rule book and the case book under 7.3.5
Essentially the batter has interfered with the catcher's throw. In HS contact does NOT have to be made. It does NOT matter if the batter accidentally or on purpose (intentional/unintentional) steps in the catcher's way. If the catcher attempts a throw it's interference.
So the best thing the batter can do is NOT move!
The catcher has to clear him. To 2nd base this is easy. To 3rd, the catcher needs to step forward (risky) or step around and behind (best).
If the batter moves he will probably end up interfering, even if he stays in the box -- although this is trickier and you will really have to pay attention -- but most likely he is gonna move into the catcher's throwing lane and then you'll have interference.
It's a delayed dead ball under 5.1.2. If the runner is put out, then the interference is ignored and play continues. If the runner is not put out by the defense, then the batter is called out and ALL runners return to their base at time of pitch.
Because it's a delayed dead ball with a guaranteed out to the defense it is possible -- although unlikely -- that a preceeding or following runner could advance and maybe even score! However, the defense has to get the out. If they don't then "Time" is called and ALL runners will retreat and the batter is out.