Over the next 4 years, India’s GDP will likely touch $5 trillion, making it the 3rd largest economy by 2027, overtaking Japan and Germany, being the fastest growing large economy with the tailwinds of demographics (consistent labour supply), improving institutional strength and improvement in governance.
So, looking at this scenario, I can speculate that India can surpass Japan within the next 12 months or so. By the year 2027 top three economies will be USA, China and India respectively.