Answer:
Federal because federalism was recently instated. Nepal, according to 2015 constitution is divided into 7 provinces/states.
Democratic because Nepal is technically a democracy, as people are allowed to vote. Even though, Nepal is categorized as flawed democracy because same politicians/parties have been in power even since democracy was introduced.
Republic because well, monarchy was abolished.
Personally, I feel it's just a publicity stunt. Generally authotarian countries tend to have fancier names like Democratic People's Republic of Korea(North Korea), People's Republic of China(CCP China), Republic of Union of Myanmar etc while democratic countries have more bland sounding names like Republic of Korea(South Korea), Republic of China(Taiwan), State of Japan, United States of America etc. Let's just hope Nepal doesn't go that way though.