Does a free throw after the halftime buzzer count in an NCAA first-half player-points prop?

Short answer

Free throws administered to complete the first half belong to that period even if the game clock already reads zero. The horn alone does not turn them into second-half points. Check the official play-by-play period and the reason the throws were awarded; an intermission technical or a different market-specific rule needs separate treatment.

NCAA interpretation of period-ending free throws; check the current competition rules