I would like to know about revokes in bridge. Can the opponents claim 3 tricks?
You mean "twice on one hand" and not "twice in one game" in your question title, as the two are very different (game is a scoring unit that can encompass many hands),
The second revoke was a failure to follow suit in the same suit as the first revoke, and
You are playing Rubber Bridge and not Duplicate Bridge;
then the following applies from The Laws of Rubber Bridge
[Law 64] D. there is no trick penalty for the established revoke
- if the revoke was a subsequent revoke in the same suit by the same player, ....
However, note the final paragraph of Law 64:
When any established revoke, including one not subject to penalty, causes damage to the non-offending side insufficiently compensated by the Law, the offending side should transfer additional tricks so as to restore equity.
The easiest example of the exceptional case would be if the revoke allowed defender to a NT contract access to a running suit not otherwise with an entry, causing a makeable contract to be set more than one trick. Clearly a one trick penalty fails to restore equity, so a greater penalty should be applied.