You asked can the parents claim a child who is away from home at a military academy.  Of course you left out child's age.  You can claim a child away from home at an educational institution.  So they can claim the child provided the child is under 19.  The support test is only that child did not provide over 50% of support.  Parents do not have to prove over 50% of support. 

Or are you asking can clients claim college tuition credit?