Instead of trying to research something which is quite obviously out of your depths, I will make things a lot easier for you-India doesn't have a stable demographic future. There's a reason the the 2021 Indian census has been delayed to 2024, after the next election.
Even according to optimistic numbers from the Indian government, TFR was 2 in 2021. If you look at the Indian population pyramid (WHO), you'll notice the cohort below 20 is shrinking at an accelerating rate, 2.7% for those between 10 and 20, but 4.4% for those under 10.
Put together it means India's TFR was likely to shrink at minimum 4% annually if COVID never happened. This matches up with India's number prior to 2014. It was at -2% yoy and went as low as 3.2% in 2013. Then in 2014, the TFR numbers magically rose to only -1.2% per year from then until COVID. During the COVID years India's reported TFR rose again to -0.8% yoy. I repeat it rose during COVID. I wonder what happened in 2014? I think someone with a penchant for making up fake figures whose name starts with an M and ends with an I came into office.
A yoy decline in TFR of 3-4% means India will be where China currently is demographically in 9-12 years. And that's just from continuing previous trends.
Let's also talk about climate change. It's basically going to hit the countries in the tropics hardest (this is also why the West doesn't actually care about it). Of the tropical countries, India's likely to be the hardest hit. 60% of India's agriculture is dependent on the rain, i.e. the Indian Monsoon. Groundwater in India is already overstressed and climate change promises to disrupt the monsoon season making its timing and amount unpredictable. Climate data shows both drought and flooding increasing in India. Furthermore, the increased temperatures and weather variability will reduce rice/wheat yields in India. Indeed there's some suspicion this has already started to take place given the numbers from 2001-2013, again the numbers 2014 onwards being powered by pure Jai Hindinum. Not to mention what increased temperatures will do to worker productivity and health.
All of that will have a further impact on India's TFR. I'm not holding my breath on India's "stable demographic future". But you don't care about any of that, so let's just say it:
JAI HIND
Indian population pyramid 2050
China population pyramid 2023
China population pyramid 2050
See how similar Indian population pyramid in 2050 is to Chinese population pyramid in 2023.
By the way, India’s GDP right now is slightly higher than what China’s GDP was in 2007.