Team India defeated Australia by 2-1 in the three-match T20I series.
The Men in Blue were 1-0 down in the series but they bounced back in style to level the series in Nagpur.
In the decider, the hosts defeated Australia by six wickets and improved their ranking by one point to 268 points – a seven-point lead over the second-placed England team.
The upcoming three-match series against South Africa will give India a chance to consolidate their lead at the top ahead of the T20 World Cup 2022 in Australia.
The Proteas hold the third spot in the team rankings with 258 points, but could replace India from the pinnacle after winning the upcoming series, starting September 28 in Thiruvananthapuram.
Meanwhile, Pakistan registered a nail-biting three-run victory over England in the fourth T20I in Karachi on Sunday. That series is currently locked at 2-2 with three more matches to go.
Pakistan are currently tied with South Africa for third place on the team rankings with 258 points, but could rise as high as second by winning the remaining three T20Is against England.
On the other hand, England will retain the second position on the rankings if they win one of those contests.
Defending T20 World Cup champions Australia, who are placed sixth, lost one point to 250 following their series loss to India.