NSSO, RBI, Chamber of Commerce,  Planning Commission, etc are the main sources of such secondary data in India.

You can contact IMF research department directly OR subscribe to the Datastream.

Thanks for your kind responses. I will try to reach the sources

Okay, am glad to hear that you will be exhaustive 

The problem is that one like IMF source rarely gives all data for all countries.

You can use CIA World Factbook about different countries, although some data can differ from IMF. For example, in Brazil  in 2015 GDP was $1.8 trln at official exchange rate, but $3.16 trln in PPP. Inflation in 2015 is estimated at 10.6%, while Central Bank discount rate is 10% since 2014. Real growth in 2015 was -3%. Industry produces 22.2% of GDP. And much more interesting data you can find in Brazil country report in the section Economy. You can do similar job with other BRICS countries.

But those data are annual. I guess you should look country by country sources to get more detailed data. Here you can get historical inflation for Russia: http://www.inflation.eu/inflation-rates/russia/historic-inflation/cpi-inflation-russia.aspx  . Also for other BRICS at the same page. I do not think that somebody calculates weekly inflation, unless during hyperinflation. Monthly inflation can also have seasonal peaks due to seasonal price change for fresh fruits and vegetables, for example.

And here is an article about BRICS; dynamics of CB interest rate, GDP and trade: http://econstor.eu/bitstream/10419/50792/1/670800821.pdf

To Brazilian data, you can search in the Central Bank and the Institute for Applied Economic Research (Ipea) websites:

https://www3.bcb.gov.br/sgspub/localizarseries/localizarSeries.do?method=prepararTelaLocalizarSeries

http://www.ipeadata.gov.br/

http://www.ipeadata.gov.br/

https://www3.bcb.gov.br/sgspub/localizarseries/localizarSeries.do?method=prepararTelaLocalizarSeries

The best sources for macroeconomic data such as those you are asking about could be World Bank Development Indicator,United Nations Conference on Trade and Development (UNCTAD), International Monetary Fund (IMF),etc., although there are countless sources out there.

You can get the data from the following website

http://www.imf.org/external/data.htm , World Economic Outlook October 2015

With Best Wishes

Dr.L.Krishna Veni

For comparable data, best to chevk the statistical databases of International Organisations, such as IMF, WORLD BANK, UN, OECD to name a few.

I think the best sources are the international organizations such as IMF, Trade Map, WB, etc.