To build a ₹2 crore retirement corpus, a person in their 50s can invest ₹1 lakh monthly in various investment options like SIPs, ET Now reported, citing a market investor. Considering the risk factor, the annualised return of 8% will make a total corpus of ₹1.85 crore, while at 10% and 12% it'll make ₹2.05 crore and ₹2.32 crore, respectively.