Captain MS Dhoni blamed India's "soft" batting for their shock 47-run defeat by New Zealand in the opening match of the World Twenty20 Super 10s.
The pre-tournament favourites and hosts were bowled out for 79 in pursuit of 127 on a slow surface in Nagpur.
Dhoni, who top-scored with 30 off 30 balls, said: "The batting let us down. There were quite a few soft dismissals.
"They definitely exploited the conditions and bowled well but we lacked adaptability."
New Zealand left out Trent Boult and Tim Southee - two of the leading seamers in international cricket over the past year - in favour of an attack containing three spinners.
Mitchell Santner claimed 4-11, Ish Sodhi 3-18 and Nathan McCullum 2-15 as nine of India's wickets fell to spin.
"The way we bowled was outstanding," captain Kane Williamson said.
"It was tough to leave out Boult and Southee but we have to adapt to the conditions. The spinners paid off today, which was very pleasing."
Corey Anderson, with 34 off 42 balls, and Luke Ronchi, who made 21 off 11, were the only New Zealand batsmen to reach 20 in a total of 126-7 after they won the toss.
Williamson said: "Whatever score we got, we knew it would be tough to chase, but we still would have liked a few more
"Perhaps we'll reflect on how aggressive we were and do that better next time."
England, World T20 champions in 2010, are the only team to win the tournament after losing their opening game.
They start their Group 1 campaign against West Indies in Mumbai at 14:00 GMT on Wednesday, after Pakistan's match against Bangladesh in Kolkata, which starts at 09:30.