Step 1: What is asked.
We need the city that hosted the 17th BRICS Summit in July 2025.
Step 2: About BRICS.
BRICS is a group of major economies. Summits move from one member country to another by turn.
Step 3: The 2025 host.
In 2025 it was Brazil's turn to host the summit.
Step 4: The city.
The 17th BRICS Summit was held in Rio de Janeiro, Brazil, in July 2025.
Step 5: Remove others.
Brasilia is also in Brazil but was not the venue, and Copenhagen and Johannesburg do not fit.
Step 6: Conclusion.
So the summit was held in Rio de Janeiro.
Answer: Rio de Janeiro