That’s unfortunate. May Allah forgive him and give you all patience.
There are two types of people who commit suicide:
1- Those who lose faith and lose hope in God. This would be a form of disbelief, and while Allah can still forgive them if he wants to, but they may not be eligible to go to Jannah.
2- Those who are not in the right frame of mind, and due to the severe depression or mental health issue, they don’t really know what they are doing. So it’s not like the deliberately committed suicide and lost hope in God. They were under so much psychological pain such that they no longer were aware of what they were doing. Such people are eligible for forgiveness and are eligible to go to Jannah.