To answer this, let’s start with simple budgeting questions e.g. Will the retired person get monthly pension? Will the retired person have any other source of income such as rent?
If the answer to above questions is no, it means that the retired person will need some income per month for basic expense. Those basic expense requirement should come from a fixed income instrument. You can check out the following schemes for senior citizens in India:
You can invest up to INR 15Lakh in each of these schemes and get ~7–8% interest every year. If the monthly expense is more than the interest of these schemes, you can invest in some other debt funds.
Once this is sorted out, you can look at investing a portion of money in a balanced or equity mutual fund. Objective is to grow a part of your money that comfortably beats inflation and grow your capital. Hence, you should consider taking some exposure to equities.
Please be careful that you don’t do a lump sum investment in equity at this stage. Given the market is at all-time high, it’s better for a retired person to put money in equity in a staggered manner over the next 2 years. For a retired person, you need to be extra careful and take very calculated market risk.
Hope this gives some idea to explore different investment options post retirement. I would also recommend that you consult a financial advisor who can analyze your specific case in more detail and provide guidance on structured investment and withdrawal.