What does the cryptic crossword clue "Measure for crowd control – delicate approach in Brazilian city (4,3)" mean?

The definition is "city". The wordplay uses a charade (building blocks). RIO (synonym="RIO") + TACT (synonym="TACT") = RIOTACT The answer is RIOTACT.

Measure for crowd control – delicate approach in Brazilian city (4,3)

Guardian Cryptic #29493 | 18 Down | 2024-09-20 flower