Gangjee, who is in his rookie year, had four birdies and two bogeys in his round.
Indian-origin Swede Daniel Chopra, who has one win this season on the Nationwide Tour, started with a 69 and was tied 40th.
With the tournament having a reputation of throwing up high-scoring winners, South Korea's Sunghoon Kang and John Mallinger opened with rounds of nine-under 63 each at the 7,110 yard par-72 Fix Den County Club.
Mallinger is playing Nationwide after missing the FedEx Play-offs. Of the 156 who started 107 were under par and 122 were at par or better.
Kang had taken a break to serve in Korean military as part of National service in March-April and his stint was reduced from two years to just one month, because he was a team gold medal winner in the Asian Games in 2006.
Brian Bateman, Kevin Kisner and Garrett Willis are all at 64s, while Paul Claxton and Nathan Green are at 65.
Modest start by Gangjee at Nationwide's Sentinel Open
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