That's true, if you are going through some legal channels. there is no such provision in real estate, especially, if you are buying one or two houses in KTM. And it won't be that simple, will it? I've not heard of such government plans for real estate where foreigners can put in money in dollars and take back home, in due course, the principal and profits in dollars.
If you are thinking of investing Rs.1 karod or two, you will need a lot of partners to go along so that you can start a size-able hydel in Nepal (we are talking about 100s of karods). But anyway, I do not have any experience in hydel, so I wish you best of luck.
Only investment I had done was through my parents and without any hope of any return whatsoever; I actually gave them to buy a good house. About 13 years ago, I was not married yet, I sent them 65k and they bought stocks. They are now very rich, plus their brand new bangala was a bonus, it appears. Of course, needless to say, my parents and siblings have kept the principal and profit for them ( I gave a gift to them). The stocks gave them a 1000 fold return. Nobody and nothing would match that, ki kaso....