Abhinav Lohan of Faridabad and Greater Noida's Mandeo Singh Pathania were in tied second, one stroke off the lead.
Mane, currently placed fifth in the Rolex Ranking, smashed seven birdies against a lone bogey during his opening round.
The 24-year-old rookie, already a winner of two tournaments this year, had a birdie-bogey start on the 10th and 11th.
He sank a 20-footer on the 10th before pulling his tee shot into the trees on the 11th that led to his only bogey of the day.
"I'm delighted with this effort as the conditions were tougher in the afternoon due to the swirling wind. It wasn't easy to judge distances. The good par save on the 15th really got my round going," he said.
"I enjoy a certain degree of comfort on this course since I played a lot of golf here during my junior days when I stayed in Union Park, Chembur, for two years. The course has undergone renovation since then but I still feel at home here. In fact, as an amateur I finished runner-up here thrice," he added.
A poor chip led to his first bogey of the day on the 16th.
The 25-year-old, a silver medal winner in the 2010 Guangzhou Asian Games, then had a dream run of three birdies and an eagle over the next four holes to gain five shots.
Lucknow's Sanjeev Kumar, Delhi's Vinod Kumar and Sri Lankan N Thangaraja were in tied fourth at four-under-66.
