Nepal

Hindu College is affiliated to DU. So you will have to apply to DU for admission. Application for DU exam can be filled online. After that you will have to give entrance exam and then based on your result you will alloted a college after cutoffs. You can apply for state funded scholarships also. They are given out on the basis of need.

If you want to do this course in Nepal, then you can apply in Kathmandu University. If you want to do it in India, then search for reputed universities providing the course. As per me, the last date for submitting the application form of government universities has gone. You may apply online in Amity University.

Civil engineering is good as it has s a lot of scope and you can get a good job. If you do diploma, B.Tech and then M.Tech, you will be perfectly achieving everything you want.

Yes, you can apply for B.Sc Agriculture in any university, and you can also get the benefit of the foreign quote.

Yes, they have a special category for NRI/SAARC students. The application process starts in October.

Where are you studying, and where do you want to work?

Most of the colleges in South Asia have similar curriculum whether it's Law, engineering, Literature or Science. Therefore, I believe it is valid in Nepal as well. As a matter of fact, a lot of students from Nepal come to India and study here and profess in their home country using an Indian university degree.