Compatibility summary
You will need a travel adapter in Sri Lanka; plug types used there differ from Brazil. Voltage differs by more than 20% — a voltage converter may be needed for some appliances.
Plug comparison
Brazil plug types: C N
Sri Lanka plug types: G
There is no common plug type between Brazil (C N) and Sri Lanka (G). You need a travel adapter.
Voltage comparison
Brazil: 127V, 60Hz
Sri Lanka: 230V, 50Hz
Voltage converter recommended (Brazil 127V vs Sri Lanka 230V).