Can Indians open an online commodity trading a/c with a company based overseas?

Can Indians open an online trading a/c for trading in commodities with a company which is based overseas, like "The Dollar" (This is the company name)?  Does it violate any RBI, Income Tax or Foreign Exchange regulations of India?

As many Indians are already having accounts with them, but as there are conflicting answers on the net, hence posting the query here and requesting replies for the same, whether this is legal or not?