Zakat should firstly be given to needy sister or brother, and then uncle, aunt and similar close relatives. Then comes neighbors or other relatives. From this point of view, your brothers or sisters who are students can take zakat from you (unless they are rich by religion, which means unless they own wealth as much as amount of nisab).
A person can give zakat to the daughter of his spouse’s brother.
A Muslim who is considered rich by religion cannot give zakat to the people like mother, father, grandmother and grandfather, spouse, children or grandchildren, for whom he is responsible to take care of. Any other people who are not rich, can take zakat from this person.