or may be the coin was minted by some one - not having the expertise to mint. So he got the legends all wrong. It is retro engraved on one side and on the revers the legends are corrupted but correct.
The Surat rupee was a well accepted coin across a very wide area and may be it was in some far off corners of the empire or may be a little out of the borders, this coin was minted.
Amit