Absolute minimum size is 326,169 Rs, which are a lumpy USD 5'000.--
Every thing under that amount is not of any thoughts, as even with this amount you will be a mosquito in any market when it comes to CME. And mosquito means that you are washed away with one slap in a millisecond in certain markets and moments and derivatives if you do not know the rules and have no protection.
Hope you very deeply do know that.
Good luck / Dan