An RRSP is a basket of eligible investments, but direct real estate ownership is not permitted in an RRSP, it has to be indirect through an RRSP eligible investment [based on real estate], such as bonds, shares, REIT units, trust units or mortgages !
You could lend money to others, you could invest in a variety of private
or public firms centered around real estate, or you could give yourself
a mortgage under certain circumstances, such as CMHC insured at market
rates, at arms-length, up to trustee dependent loan-to-values [OlympaTrust, TD, Laurentian B2B Trust, CWT, ... to name a few of the trustees that allow mortgages or private shares/trust units]