Under 600 is "less than perfect" in a very broad sense of the definition. Truthfully, under 600 would be considered bad credit. Not unsalvageable, but definitely at the bottom end of the spectrum.
With that being said, there are some options. FHA would probably be the preferred option because it will have the best interest rate and lowest down payment (3.5% down payment required). We are able to go as low as a 580 credit score, but be aware that just because you meet the minimum credit requirement isn't a guarantee of approval. We also look at income, debts, and assets as well as the "why" behind your credit scores.
Feel free to shoot me an email or give me a call and we can see about getting you approved for a loan. If FHA won't work then I have some other options that require larger down payments (20% or more), but they aren't as strict on the credit scores.
Sr. Mortgage Loan Originator
Luxury Mortgage Corp