"These guys (India) are a very good unit, world champions and Champions Trophy holders. To have a series win against them, and to do it in Hamilton which is as close as a subcontinent wicket that you'll get ... To win twice against them here was superb," Mills was quoted as saying in a website.
The 34-year-old veteran said he had to rely on his experience against the world champions who possess a great batting unit.
"I've always been confident in myself because my stats suggest that I should be in there. I've always felt I've bowled well and contributed to the team performance."
New Zealand have taken an unassailable 3-0 lead in the series with one match to go.