If someone retires with a Rs 4.5 crore corpus and invests that amount in a fixed deposit (FD) at a 7% growth rate, their interest in one year can be approximately Rs 37.33 lakh. Such a high interest income can put them in a 30% income tax slab, and if there is no other income, the investor will end up paying around Rs 7 lakh as income tax under the new tax regime. So, the net income after tax in one year will be around Rs 30.33 lakh.Is there a way you can get better post-tax returns that rise every year to take care of inflation? Yes, there is an alternative system to cut the tax bill where you can invest the corpus in a mutual fund and start a systematic withdrawal plan (SWP) to get a regular income. The benefit of doing so is that you withdraw both the principal and gains, but you need to pay income tax only on gains and not on the principal amount.Moreover, long-term capital gains on equities are exempt up to Rs 1.25 lakh in a given year and gains above it are taxed at a much lower rate of 12.5%. Higher is your investment in equity instruments with a long-term horizon, the lower your tax outgo. As a result, your tax liability remains much lower if invested in equity MFs when compared to FD, if the amount you invested is Rs 4.5 crore.How to invest Rs 4.5 crore in tax-efficient wayIf you have a Rs 4.5 crore corpus, you can invest the amount in a mutual fund and start an SWP for monthly withdrawals, but only if you have the desired risk appetite to invest in growth assets like equities. Rather than investing the entire sum in one fund, it is better to diversify and invest the corpus in five buckets of liquid, debt, equity savings, aggressive hybrid and equity mutual funds. While there could be many ways to diversify your investment, here we give one such allocation of a Rs 4.5 crore corpus.Asset allocation of Rs 4.5 crore investment for retirement Investment bucket Withdrawal duration Return assumption Allocation Liquid Fund Year 1 5% ₹30 lakh Debt Fund Years 2–3 7% ₹60 lakh Equity Savings Fund Years 4–5 7.50% ₹80 lakh Aggressive Hybrid Fund Years 6–7 10% ₹45 lakh Equity Fund Year 8 onwards 12% ₹2.35 cr Total corpus — — ₹4.50 cr ET Online