As per ICICIDirect NRI withholding tax (WHT) is deducted at source at the rate of 30.90 % (30% Tax rate, & 3% Cess)
Some other points which might help other NRI
TDS is deducted end of every month on net profit for that month.
In case of loss no refund is given. Loss it is carried forward to the next month and adjusted against the profit in subsequent months in the same tax year.
However tax deducted on cumulative net profits in one month can not be refunded or adjusted in case there are losses in subsequent months.