India's tour of New Zealand saw Mandhana's formidable form, which helped her side win the first two games and clinch the ODI series 2-1 by huge margins, resulting in the 22-year-old becoming the number one ODI batswoman along the way.
Bates said: "She [Mandhana] is a classy player and loves pace on the ball. She has scored at a very good clip in the one-dayers. So we will have to come up with good plans to reduce her boundaries in T20Is."
The Indian opener, adjudged the Women's Cricketer of the Year and named in T20I Team of the Year by ICC in 2018, played a crucial role in India's campaign at the World T20, scoring 178 runs in five matches at a strike-rate of 125.35.
As New Zealand reflect back at the drawing board ahead of T20I series, Bates aims to overcome India, saying "with the change of format we want to show how well we can play T20I cricket after missing out on the semi-finals in the last World Cup".
In the backyard of New Zealand, India dominated the Kiwi players as they produced a master-class of adapting to flat wickets in the first two ODIs, before collapsing in the third. The Kiwi bowlers rattled the touring batting order in Hamilton to give New Zealand a consolation win as they remained clueless and unsuccessful until the final match.
"Unfortunately by ensuring we have televised matches we have played after the men on used wickets. Traditionally the challenge for Indian teams touring New Zealand is the extra pace and bounce. By playing on used wickets we did not have wickets that suited our bowling attack as well as they could have."
Warming up with the Women's Big Bash League in Australia, Bates secured a place on the WBBL top run-scorers list and picked up nine wickets. Her New Zealand and Adelaide Strikers teammate Sophie Devine, too, had a purple patch, scoring 556 runs, including an unbeaten 99 and 95 and scalping 14 wickets in the tournament.
Lea Tahuhu took 14 wickets for the Melbourne Renegades, while New Zealand skipper Amy Satterthwaite led the Renegades to the semi-final that ended in heartbreak in the Super Over.
For India, T20 skipper Harmanpreet Kaur and Mandhana struck two fifties each in their respective tallies of 310 and 318 runs.
Having faced the Kaur-led side in the World T20 opener, where the Indian skipper unleashed a brutal hundred to raze New Zealand by 34 runs, Bates said, "As captain, Kaur seems to have clear set plans that she demands her bowlers to stick to. She is an attacking batter and likes to take the game on and this also probably shows in her captaincy."
Bates stepped down from the post of New Zealand skipper after six years in charge, handing duties to Satterthwaite, who, she believes, is "very calculated and plans extremely well with bowlers off the field to ensure we are clear heading into each game".
India Women and Men will face New Zealand's White Ferns and Black Caps on the same day in a T20I double-header.
Bates, who has witnessed the rapid rise of women's cricket over the past few years, believes that it has "benefited massively from playing before the men in televised T20I matches. It is always a great atmosphere when both men's and women's teams are competing at the same ground."
The cricketing festivities will begin with India Women and White Ferns followed by India Men and Black Caps at Westpac Stadium in Wellington on February 6.