Where should one invest in India to get the best returns?

The best investment plans with high returns, are equity mutual funds and stocks. High return investments usually come with higher risk. Hence is is very important to invest as per your ability to take risk and willingness to do so (see link below). These are two different things, but very important.

You could invest in small cap stocks and small cap mutual funds, but the risk is higher and you need to be prepared for them. Our mid cap portfolio circa 2014 gave a high 40% return cagr over the last five years. Many mutual funds also have given higher returns, but then it is important to stay invested in good funds and stocks. Your time in market is more important than timing the market.

If you cannot take higher risk, then you can invest in debt mutual funds, government instruments like PPF.

Avoid investments that deplete tax for you, such as bank Fixed Deposits. There are better alternatives to FD in the form of debt mutual funds that offer high security (such as government security focused funds).

Useful link: Find your risk profile