She could start by asking him what's wrong in a gentle voice. Then, depending on his answer, she might offer practical solutions if it's something solvable, or just be there for him if it's more of an emotional issue. For example, if he's crying about a fight with Ron, she might try to mediate. If it's about his parents, she'll just hold his hand and listen.
She probably comforts him right away. Hermione is a very empathetic person. She might give him a big hug and let him cry on her shoulder.
Often, Harry will offer her a handkerchief or a tissue if there is one available. He might also put his arm around her in a comforting gesture. In 'The Common Room Crisis' fanfic, he does just that and then stays with her, listening intently as she pours out her feelings. He is patient and understanding, which is in line with his character in the original books. He tries to make her laugh or at least smile by sharing a joke or a funny memory. This shows his deep friendship and care for Hermione.
Hermione would likely be a mix of disappointed and worried. Disappointed because Harry is usually responsible, and worried because she cares about him. So she'd probably try to figure out why he got drunk in the first place.
He might be initially startled. Snape is used to seeing Hermione as a strong - willed and confident student. So seeing her crying could catch him off - guard. But then he might quickly put on his usual cold facade and ask her curtly what's wrong.
She might be initially shocked. After all, Draco is usually seen as this tough Slytherin. But then she could feel sympathy. For instance, she might offer him a handkerchief without saying much at first.
Harry might immediately rush to her side and comfort her. He could put his arm around her and ask her what's wrong in a gentle voice.
She might immediately go to comfort him. Annabeth is a strong character, but she also has a soft side for Percy. She could hold him and let him cry it out without asking too many questions at first.
Sirius would probably be very concerned. He might immediately ask her what's wrong and offer her a handkerchief to dry her tears. He has a bit of a wild side, but he also has a big heart, especially when it comes to those he cares about or sees as in need of help.
Harry might be initially shocked. He's used to seeing Draco as this tough, arrogant Slytherin. But then, he could feel a bit of pity. He might approach Draco tentatively and ask what's wrong. Harry has a good heart, and despite their past differences, he wouldn't just leave Draco crying. He may even offer some words of comfort or a handkerchief if he has one.
Fleur could be a bit hesitant at first, not fully understanding the situation. But once she realizes the gravity of Hermione's state, she becomes determined. She might call for help from other reliable wizards or witches she knows. Fleur would also comfort Hermione, telling her that she's safe now and that they will find the culprits. She may use her Veela charm in a subdued way to soothe Hermione's distress.
Ginny's reaction could also involve a sense of helplessness at first. But then she'd quickly gather herself and use her resources. For instance, she might call on her friends and family for help. She'd be by Harry's side constantly, using her presence to comfort him and also using her knowledge of magic to try and ease his pain.