The owners are an older couple who aren’t necessarily real estate investors, I think they just owned this for a tax write off.Any help is greatly appreciated!

You aren't.

However when they spoke to their mortgage broker, the rates were around 6% for a 5/1 and 60% LTV for example since they have more than 4 investment properties the terms aren’t favorable.

Aren't those hard and expensive to get in the first place?

We always follow whatever checkout guidelines are included in the instructions and be sure to do simple things like take out the trash, strip beds, etc, even if they aren't on the list.

That property that looks to be a home run could wipe you out if you aren't careful.

Good ones aren't cheap. 

Commercial lenders can do whatever they want, but the terms aren't as nice.Check with your local banks first and see what they can offer. 

If we let him out but require him to pay rent untill we fill it we could potentially not get the rent out of him for that as well.Should we say we will sign a lease extension with aren't bump after the 6 months?

You would lose out on some of the tax advantages, but then also wouldn't be paying property taxes and insurance on two residences that aren't being used for investment purposes.