For State tax: most likely scenario is that he has to file to the state where he earned money as a non-resident. And for the home state, he will have to file as a resident. He will have to figure out how much tax he has to pay to the non-resident state (if tax withheld, he can get refund or even pay more). For the home state, he will get credit for any tax he paid to the other state.
For fedearl tax, if you claim him as a dependent, he can not claim education credit ( see 8863 instruction), only you can claim. Since your income is too high for the credit, you will have to try different filing ways, see which way is better. Depennds on how much he earned, if more than 20K, let him file completely independent might be the best way: he has capital deduction and standard dedcution, this is about 9K, and then 11K for tax, ans he can get all pennies back by American Opportunity credit. You will not have the capital deduction from you tax return, and this is only 3700 dollar, and the maximal tax for 3700 is 1295, much less than American Opportunity credit.
