There has been a lot of news about bitcoin banned in Nepal, here are some of my thoughts on it .
NRB, like the Reserve Bank of India, European Central Bank or US Federal Reserve, is a Central Bank, which is not really a bank. It's a government institution that makes monetary policy. It's designed to have a monopoly. It'd be a disaster to have parallel central banks.
Since Nepalese Rupee has a fixed exchange rate with Indian Rupee, we often find ourselves in the same situation they are in and need to make monetary policies that are similar to theirs. For example, when their currency gets strong, ours does too. It would also be a disaster if NRB tried too hard to appear different from RBI.
In this case, as I linked above, NRB is parting ways with RBI. Bitcoin is unofficially legal in India, and about to be officially legal as well.
Making it fully legal requires a regulatory framework, which takes time and trouble to create, and uses resources to enforce. Probably this is why Nepal hasn't done it yet. Perhaps they can eventually just copy India's framework and make it legal too, but I'm guessing Bitcoins are a low priority item for them.
May be legalized in coming year ?