Check with a variety of apartment complexes and find out what their policies are. Some apartment complexes rent to individuals with prior felony convictions who have just been released from prison. Others may not be comfortable with that. It is up to the complex.
There is nothing you can do except try with as many landlords as possible. Some are going to care more about misdemeanor convictions than others. As you said he cannot get any of these expunged until 3 years has passed, so for now try as many landlords as you can.