Dear Talati,
Residents can invest upto 200K USD annually. As i mentioned earlier, The RBI does not specifically categorize where you can and where you cant make investments, though the LRS (Liberalized Remittance Scheme) Schedules mention, Margin is not allowed.
Regarding taxation - When you transfer you transfer for business investments abroad. When you receive your funds back or book profits or losses, you mention profits or losses from business investment abroad.
You can confirm this with any CA or even with alpari which has its office in India (
www.alpari.co.in)
With BR,
Mash