A tweet by billionaire entrepreneur Elon Musk on India's declining birth rate has gone viral on social media platform X, attracting millions of views and sparking debate.Commenting on a post about India's fertility trends, Musk wrote: "India's birth rate has fallen below replacement. Among those most educated, India's birth rate fell below replacement many years ago."Musk has repeatedly voiced concerns about falling birth rates across the world, arguing that declining fertility poses long-term demographic and economic challenges.The post he shared claimed that India's total fertility rate (TFR) has fallen below the replacement level for the first time in the country's history, dropping from 2.3 to 1.9 in just a decade. It also noted that Delhi's fertility rate has declined to 1.2, lower than that of Finland.— elonmusk (@elonmusk) At the time of writing, the post had garnered more than 4.4 million views.The tweet triggered mixed reactions from X users.One user wrote: "Funny how multi-billionaires worry about birth rates. India doesn't need lectures from Elon. It needs better jobs, cleaner cities, stronger institutions, corruption-free leaders and higher living standards. Population size alone isn't a success metric."Another user commented: "India's birth rate just nosedived below replacement; Delhi's already at 1.2. Educated people moved away from large families years ago. Hustle over heirs is becoming the global norm."The issue has drawn increasing attention in recent months. According to the 2024 Sample Registration System (SRS) report, India's total fertility rate has declined to 1.9 from 2.1, pushing most states below the replacement fertility level of 2.1 children per woman.Only six states—Bihar, Uttar Pradesh, Madhya Pradesh, Rajasthan, Chhattisgarh and Jharkhand—remain above the replacement level, while Delhi recorded the country's lowest TFR at 1.2.The replacement fertility rate of 2.1 is considered the level at which a population replaces itself from one generation to the next. Demographers warn that sustained fertility below this threshold can eventually slow population growth and, over time, lead to population decline.The report also found that Bihar recorded the slowest decline in fertility over the past decade, while Delhi and Tamil Nadu saw some of the sharpest drops despite already having relatively low fertility rates.Last year, United Nations Population Fund (UNFPA) 2025 State of World Population (SOWP) Report said that India’s total fertility rate has declined to 1.9 births per woman, falling below the replacement level of 2.1, which means that on average, Indian women are having fewer children than needed to maintain the population size from one generation to the next, without migration.India's current population is over 1.46 billion and the country surpassed China in 2023 to become the world’s most populous nation.“Although its fertility rate has declined over the years, India has a population of well over a billion, and wide inequalities persist, despite significant improvements in health and education. Maternal mortality and gender discrimination remain high. Early marriage and pregnancy contribute to excessive maternal death among women under the age of 24,” according to information on the UNFPA website.