How to earn inflation-adjusted income of Rs 3 lakh a month

Considering long-term inflation rate at 6% a year, you will need a corpus of Rs 4.45 crore

I want to earn an inflation-adjusted income of Rs 3 lakh per month for the next 15 years. What should be my corpus and what instruments should I invest in to have a reasonable certainty of getting this amount after providing for inflation and tax (assuming highest tax bracket).
— Nripjit Singh Chawla
 
You will require a corpus of Rs 4.45 crore for your inflation-adjusted income need of Rs 3 lakh per month for the next 15 years. We have considered long-term inflation rate at 6 per cent a year and weighted average post-tax returns from investment at 8.85