Is it possible to sell a home in less than 4 months?

A relative is a businessman and has a $600k mortgage in northern Chicago. His business is falling under and he can't make his mortgage payments plus other bills, so his only option is to sell it. Luckily, he has 4 months of emergency savings, so his plan is to sell it before those 4 months are up. But Is it possible to sell the home, finish the closing process, and receive however much equity you own all in 4 months?

Also, what if there are no offers? Foreclosure, right? What happens to your equity/down payment if you go through foreclosure?

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