taxability of income earned in Nepal

A person whether a citizen of India or not becomes a resident of India if and only if he resides in India for more than 182 days during the previous year or for more than 60 days during the PY and 365 days during the preceding 4 PYs.  So in your case, the person has been in India only for one month, and the source of Income is also not from India.  Hence the income earned from Nepal is fully exempt from tax.