https://www.nytimes.com/interactive/2021/05/25/world/asia/india-covid-death-estimates.html
The Times in collaboration with a range of experts modeled rough estimates for the true pandemic scale in India. This is necessary as India undertests substantially and has very incomplete death reporting. It will be awhile till we get accurate excess death figures from India that may better show the true scope, but for now these scenarios are a good guide.
They arrived at these scenarios by using national and local serosurveys taken throughout the pandemic and by using age-based IFR estimates from other studies. India is a very young country, so its average IFR is lower than it is for the US.
Even the most conservative scenario has twice the number of deaths as the official counts. It assumes cases are being underreported by 15x the low end of expert estimates with an IFR for India of 0.15%.
The more likely scenario assumes 20x case underdetection, a slightly lower multiplier than the average of the national serosurveys and an IFR of 0.3% in line with the CDC age-based IFR estimates. Deaths are over 5x the official counts.
The worse scenario assumes the high end of serosurveys at 26x underdetection with the high end of age-based IFR estimates. Deaths are 14x the official counts.
This is a big range, but anyway you look at it, India's still ongoing pandemic has been severe.