There were about 1,800 Indian soldiers present during the evacuation. These were from four mule companies of the Indian Army's Service Corps, recruited mainly from the area around Rawalpindi, in what is now Pakistan. Their role was to ferry supplies forward to the troops over difficult ground, or where roads did not exist. Of these four companies, the majority of one was captured by the Germans, with the remainder being evacuated. The ships carrying out the evacuation mainly came from the British Merchant Navy. While 132,000 of its sailors were British, some 40,000 were from India or Pakistan. For more information, see here, and for more context here and this thread.