Most people would be surprised to know that in recent years India has only been slightly above the nominal replacement rate of 2.1 – and now it is below that:
India’s most recent National Family Health Survey, which is conducted every five years by the Health Ministry, was released Wednesday and showed the total fertility rate (TFR) across India dropping to 2.0 in 2019-2021, compared with 2.2 in 2015-2016.
https://www.washingtonpost.com/world/2021/11/25/india-birth-rate-replacement-population/
While COVID could be a factor for part of the surveyed period, consider this:
The proportion of women who used contraceptives rose from 54 to 67 percent, according to the national survey, while those who reported an unmet need for contraceptives fell. The proportion of teenage marriages has also decreased…
On top of that, as we see everywhere else, urbanisation is a big factor:
In cities across India — as in other countries — women are opting for fewer children: The urban fertility rate is 1.6.