All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First of all, you should know that a Muslim student should do his best and endeavor to attain a high level is his studies (which should be in permissible fields) as the Prophet said: "Allaah loves when a person does a work, that he does it perfectly and to his best ability." The Prophet further said: "A strong believer is better and is more beloved by Allaah than a weak believer." [Muslim].
What is important is that your studies should be in permissible fields, in permissible business, and everything which is related to it should be permissible.
As regards working in the above institutions, after you and your brother graduate, then these institutions are included in one of the following three probabilities in regard to its activities and business:
1- The origin of its activities is forbidden in itself, like banks dealing with Ribaa, and commercial insurance companies and the like. In such case it is not permitted for either of you to work in these kinds of companies.
2- The origin of its work is not forbidden, but it carries forbidden works and contracts, like issuing bonds and the like. It is permissible for you to work only in permissible jobs in these kinds of companies and in which there is no help in something that is forbidden.
3- The origin of its work is permissible and its activities are permissible; in which case it is permissible to work in these kinds of companies without any restriction.
Allaah Knows best.