The Government of India permitted establishment of National-level Multi-Commodity exchanges in the year 2002 and accordingly three exchanges have come into picture. They are

• Multi-Commodity Exchange of India Ltd, Mumbai (MCX).
• National Commodity and Derivatives Exchange of India, Mumbai (NCDEX).
• National Multi Commodity Exchange, Ahmedabad (NMCE).

Some of the most popular exchanges around the world  

• New York Mercantile Exchange (NYMEX)    
• Chicago Board of Trade (COMEX)
• London Metals Exchange (LME)
• Chicago Board Option Exchange  (CBOT)       
• Tokyo Commodity Exchange    

Working Hours For The Exchanges:

Commodity Exchanges (MCX and NCDEX) function from 
Agricultural commodities from 10 am to 5.00 pm
Non  Agricultural commodities from 10 am to 11.30 pm

India Regulator For  The Commodity Exchanges:

Commodity Exchanges are regulated by Forwards Market Commission (FMC): Forwards Market Commission is under the purview of the Ministry of Food, Agriculture and Public Distribution.

Risk Of Commodities Markets Compared To Stock & Bond Markets:

commodities markets are less volatile than the stocks and this has been statistically proven. Therefore it's relatively safer to trade in commodities.
However all investments are subject to market risk and depends on the individual decision. There is risk of loss while trading in commodity futures like any other financial instruments.