You have the name right. These tribals are known as Brokpa as well as Drokpas. Their villages of Dah and Biama, are along the banks of the River Indus and you can reach there by road from Kargill town (50km or so).
For arriving Drokpa Village you have two option. One from Leh and another from Kargil via Batalik. For this you have to collect Inner Line Permit. At leh you will get it from D.M. Office. The Hotel Owner can also collect it for you at a nominal charge of Rs.50/- excluding specified fees. Though I have visited through the villages through Kargil. But o the way I have been about to return to Kargil for not collecting Inner Line permit. The drivers of Kargil will told you for not collecting permit as it is not necessary. But it is not true.