Hypothetical Situation ???

[BillyMac]

NFHS 3-3-1-C: During multiple free throws resulting from personal fouls, substitutions may be made only before the final attempt in the sequence and after the final attempt has been converted. EXCEPTION: When a player is required by rule to be replaced prior to administering the free throw(s), then all other substitutes who have legally reported may also enter the game.

Both Team A, and Team B, have one seven foot player, A7, and B7, who both happen to be resting on the bench when the following play occurs. Five foot point guard A1 fouls B1 while B1 is in the act of shooting an unsuccessful two point field goal. It's A1's fifth foul. Substitutes A6, and A6, are already at the table when the official reports the foul. After reporting the foul, and notifying the coach, and A1, regarding the disqualification, Team A sends seven foot tall A7 to the table to replace disqualified five foot tall point guard A1. The official beckons A6, B6, and A7 into the game. Seeing a mismatch about to occur, Team B immediately sends seven foot tall B7 to the table as a substitute.

By rule, may the official beckon B7 into the game, or must the official wait until after the first free throw to beckon B7 into the game?