Ok, to get organised, has he got a list of every assignment he needs to submit and the dates to do so on what he has missed?
Then a list of what the content of those assignments are, and what resources are available for him Ie on line lectures, study notes, books etc, to enable him to complete them?
Does he have any exams he has missed? What study is required for those, and the content?
Then the order in which any elements were taught in case it increases in complexity?
Then he needs to understand what’s required from now on, what lectures, what contact time, what assignments etc, and how long they realistically take, what self study is required, because he needs to plan his days round doing his current assignments, and then factoring in the previous ones.
Once he has all this then putting it all together into a daily work plan with him, would help him get organised.
He can then start collating the resources he needs, how he accesses study notes, on line lectures, books etc,
In the mean time, how is he feeling about doing the current work? Is he able to do it, if he’s not got the back ground of what has been previously taught Ie can he understand it if he’s starting from scratch on it at this stage?
It might be then also worth factoring in, how he gets up to speed on what is currently being taught, so he stands a chance.
I’d then ask him to review it with his personal tutor, to see if his plan works or he is missing something.. potentially he could ask to see the personal tutor say weekly or fortnightly to discuss his progress additionally to the current contact time, depending on if they have the time available.
I’d factor in daily calls with him to go through the plan and check each element has been completed and see how he is faring. So pick a time that suits you both, and spend an hour or so each morning or night going through what he’s achieved that day, and any areas he is struggling, start to then amend the plan accordingly, so he can spend extra time to deal with those issues.