I totally agree with truenepalidude.
Do not send your little brother to study for his undergraduate degree in US if your family cannot support him financially. With little research, you can know that an international student in US is legally allowed to work for only 20 hours/week  and that too is only on-campus job. In summer and winter holidays (roughly around four months), he can work for 40 hours/week.
This earning will barely be enough for his living cost and little or no money will be left for his tuition fees. Then he'll be compelled to work illegally and overtime which can affect his studies. His physical as well as mental health can be affected as well due to huge pressure of financial worries in addition to worries related to studies and and maintenance of legal status.
I strongly advise parents and guardians in Nepal not to send their teenage kids for undergraduate degrees in US, unless they get 100% scholarship which is again very unlikely. Instead, please let them get undergrad degree in Nepal/India with good GPA score. Then they can come for graduate degree to US. In most of the cases, Universities provide financial assistanceship in grad programs.