The 22-year-old Joshi, who needed just 23 putts for the round, closed his round with three birdies in a row to share the lead with Casey O'Toole of the United States, who also shot 66.
Two other Indians -- Himmat Rai (72) at tied 32nd and Feroze Garewal (75) at tied 85th place -- are also in the field.
Joshi and O'Toole grabbed a one-shot lead over Rory Hie of Indonesia, David Gleeson of Australia and local stalwart Lin Wen-tang.
Playing in his first round of competitive golf in slightly over a month, O'Toole struggled early in the round before hitting four straight birdies from the 15th hole. He added two more birdies on 16 and 18.
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Since it was inaugurated in 2010, the ADT has grown from five events in the first year to a record 21 tournaments in 2014.
The ADT has announced a provisional 2015 schedule of a minimum 24 tournaments with several more to be announced in due course. The ADT will continue to reward the top-five finishers on the Order of Merit at the end of this season with Asian Tour cards for 2016.