Build House for Renting.

Cannot answer without more information.
Your very general inquiry presupposes that:
1. You are a nepali citizen, of course
2. You already own the required plot of land on which you plan to build. In general terms, that would mean a plot of land of say anywhere from a minimum of 3-10 annas or thereabouts; or perhaps more in terms of ropanies.
3. That this plot of land is located in a constructible area, so that later, you can apply for and obtain your required building permit
4. That you are the sole owner of that plot of land, and can provide evidence of this with land certificate; property duly registered at your local Land Registry, of Ward or area where land is situated.
5. That the land in question is free of any liens, loans or advances,  third party claims or outstanding mortgages.
If you can confirm same, and think you meet all those criteria, the next logical step would be for you to discuss your project in detail with a qualified nepali architect here and ask him to:
- prepare all the preliminary plans, blueprints and the like
- ask him to prepare initial costings
After that, a process which may take several months, I would then advise that you visit your nepali banker and submit your project to him. If you are an established client of that bank, and they know you, that will help. Right now, the banks are lending million of rupees every day, and a good time to raise the money for such a project. If your project is viable, and you have a clean banking record yourself, you should have no trouble in raising all the funds you require right here in Nepal, from your own bankers. Good luck to you, and on your project.