if a college doesnt have the major i want, can i request the college to adopt the major? and start teaching it?

Sure, you can request anything you want. But don't expect them to actually do anything about it unless at least a few dozen more people request the same major. They aren't going to blow their budget and cater to you personally. If you are serious about bringing this major to your school, then at the very least you'll need a petition with a good number of signatures.

If you think you could put together the major you want from classes they already offer (which is something you can and should research first), you could ask them about independent study and self-directed majors. But it's a lot of work and investment for a college to set up an entirely new department, and they're not going to do it unless there's a lot of demand from the student body as a whole.