The most common and most likely answer to this crossword clue is the 5 letter word NEPAL
I've seen this crossword clue in Independent
N
E
P
A
L
More clues leading to the result NEPAL
- Country lane winding around first of poplars
- Friend from Newcastle, perhaps, in mountain country
- New European friend’s country
- Land in US city prison the wrong way
- Country friend from the Sunderland area?
- Plane flies around mountainous country
- Plane crashes in mountainous territory
- State one’s a friend from Durham?
- North-eastern China is land with no coast
- Mountainous region in northeast China
Buddy explains!

The straight part
We know that "republic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case republic = nepal.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.