In reply, Sri Lanka were bowled out for 137 as Arshdeep Singh took three wickets, while Hardik Pandya, Umran Malik and Yuzvendra Chahal took two wickets each.
Saturday’s victory was followed by India winning the first T20I by two runs, while Sri Lanka won the second game by 16 runs.
The teams will next meet in three One Day Internationals, with the first match being played in Guwahati on Tuesday.