A 25-year-old person needs to invest ₹24,000 in a monthly SIP with a 12% rate of return to build a ₹15 crore retirement corpus by age 60, according to the SEBI's SIP calculator. The total investment value will be ₹1.01 crore. However, a 30-year-old would need to invest ₹43,000 monthly in SIP in order to make a ₹15 crore corpus.