How to break an unknown ciphertext - transposition of some kind
If you know for sure that it is a transposition of some kind you can chek
the average frequency with which the various letters appear in the natural language of the plain text and then compare them to the frequencies of letters in the cyphertext. You can easily find this data on google, here is the example for english.
This method works only if the transposition of the letters is always the same, for example: letter $n$ of the ciphertext = letter $n$ of the plain text + 10.
If your key use columnar transposition you need to work out the column lengths by dividing the message length by the key length. Then you can write the message out in columns again, then re-order the columns by reforming the key word.