Yes, you can diversify investments in a Registered Retirement Income Fund (RRIF).
The money in your RRIF can be converted into a number of different savings and investment products without restriction. You can invest in bonds, market-linked guaranteed investments, mutual funds or even stocks.
Before investing, you should determine your financial objectives, the desired rate of return, maturity date, time frame in which you will need the funds and your tolerance to market fluctuations.
Remember that you will need to withdraw a minimum amount from your RRIF annually. Make sure you have some short-term investments to this end, but the rest can be invested for the medium- and long-term.
Pay less tax, too!
If your portfolio includes both registered and non-registered investments, you may want to put the interest-bearing investments into your RRIF to be able to defer paying taxes on interest earned. Putting your savings, which are more heavily taxed, into your RRIF means you can defer taxes until the time of withdrawal. Not only that, but you might be able to benefit from a lower personal income tax rate.
As for products that pay dividends or even capital gains, which are taxed at a lower rate, you may be best off putting them in the non-registered portion of your portfolio.