If a spell is countered, does it count as played for Battering Ram discount effect?

No — a countered spell does not count toward Battering Ram's cost reduction.

Per Rule 425.1.b, a card that is Countered is not considered to have been played. Since Battering Ram's ability checks how many cards you've played this turn, a spell that gets Defy'd or otherwise countered never reaches that threshold. The spell is removed from the chain before it finishes playing, so Battering Ram won't reduce its cost for that card.