The most common and most likely answer to this crossword clue is the 6 letter word ANKARA
I've seen this crossword clue in The Daily Telegraph
A
N
K
A
R
A
More clues leading to the result ANKARA
- Unlimited deposit linked to Saudi capital
- Capital invested in bank? A racket
- Paul, the American singer and artist, in a foreign city
- Capital in bank a racketeer deposited
- Capital invested in Bank Arabia
- Burbank -- a rather gripping city
- Support reportedly required by Austria’s first capital city
- Capital invested in bank? A racket!
- A capital rank Arab holds
- Some bank a rand to achieve capital
Buddy explains!

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.