According to CEBR India to become 3rd largest economy by 2031:

Third largest Economy by 2031:

The Centre for Economics and Business Research (CEBR) from the United Kingdom has predicted that the Indian economy will become the world’s third-largest by the year 2031. In the year 2022, India is set to regain its sixth position in World Economic League Table (WELT) from France, as per CEBR. The projections have assumed 6 per cent real growth rate, 5 per cent inflation and 2 per cent depreciation. Currently, India is the world's sixth-largest economy by nominal GDP and the third-largest by purchasing power parity (PPP).

Pushed back by three years:

In 2017, BofA Securities had expected the Indian economy to achieve this feat by 2028, which has been pushed back now by three years due to the Covid-19 pandemic. In the year 2020, India’s GDP had witnessed a contraction of 7.3% due to the COVID-19 pandemic and subsequent lockdown leading to constraints on economic activity. India has witnessed a large scale spread of infections and has the third-highest death toll worldwide, behind US and Brazil. However, with the help of emergency aid and prompt measures taken by the Indian government, the country has recovered from the second wave of COVID-19.