leopradhan,

What a lovely flower! That is a tuberous begonia.

I see that you live in Nepal. I understand that Nepal has various climates: Mountain, Hill and Terai. In which type of climate do you live? If you live in a tropical/subtropical region and have hot summers with warm nights you'll never have much luck with tuberous begonias. They are hybrids of high altitude tuberous species, so unless they get relatively cool nights you can't grow them successfully. In the southern warm regions, these are generally enjoyed as an annual in the spring because they cannot be kept alive during the hot, humid months.

If you are up in the mountains, you may have much better luck!

Carol