Yadav is the best-placed Indian with 805 points in the batting list headed by Pakistan's Babar Azam.
Iyer, who had hit a 40-ball 64 in the final T20 after a subdued show in the first four matches of the recently-concluded series against West Indies, has 578 points.
Among bowlers, spinners Ravi Bishnoi and Kuldeep Yadav also made massive gains in the rankings.
The 21-year-old Bishnoi, who scalped six wickets in two matches in the T20I series against the Windies, galloped 50 places to take 44th position, while Kuldeep, who had a three-wicket haul in the last game, leapt 58 places to 87th.
However, senior pacer Bhuvneshwar Kumar dropped a spot to 9th despite having had a good outing in West Indies.
South Africa's Reeza Hendricks is the main gainer in the T20 rankings, moving up to 13th position with knocks of 74 and 42 in a 2-0 series win over Ireland.
South African spinner Keshav Maharaj is up 10 places to 18th among bowlers, while fast bowlers Lungi Ngidi (23rd) of South Africa and Lockie Ferguson of New Zealand (31st) are others to move up the chart.
Pakistan captain Babar Azam has managed to hang on to his mantle as the No.1 ranked T20I batter while Australian Josh Hazlewood and Afghanistan's Mohammad Nabi continue to top the chart as the best bowler and all-rounder respectively.