Hi Kah22
Yes, he can put in for another claim. However, I would encourage you to get hold of the PA4 assessment report - if he had a telephone assessment - if you don't already have it. It's good to know exactly why he was turned down, or it might happen again. Do have a good look at the guide so you're up-to-date with the best way to answer questions.
benefitsandwork.co.uk/guides-for-claimants/pip BIS