[ryac]

What is the penalty for a renege immediately after the trick has been played

[Stephen Tu]

If you discover you have reneged (aka revoked), immediately after the trick, before you or your partner has played to the next trick, you should halt play & correct the revoke by following suit and withdrawing the card originally played. The card you originally played becomes a major penalty card. You must play this card at the first legal opportunity. If your partner gains the lead before you have played the card, the declarer has lead restriction options (require/forbid lead of that suit, in which case the defender can pick up the card and play whatever legal card he wants, the card is no longer a penalty card; or allow any lead while the card remains a penalty card)