Unlike Equity F&O, the quantity in the currency and cross-currency derivatives contracts are to be entered in lots.
For instance, if you wish to Buy 20000 Qty in a EURINR contract, you can just enter 20 in the quantity section of the order window as each lot of EURINR consists of 1000 Qty Euros. Therefore, 20000/1000 = 20 Lots.
Below is the table of the Currency and Cross-Currency pairs along with their lot sizes: