It is not hard at all if your father was born in Nepal and holds a Nepali citizenship.You just need to show his citizenship. and getting citizenship if you have relatives in government offices or by paying money is not true at all. it may have happened in some cases in some Terai districts bordering india, but one or two such cases don't represent the true picture. If one takes such an example from news reports and believes it to be the method of getting citizenship in Nepal, then may god help him.