The scribe made a mistake and for the akṣara "ccha" wrote two vowel diacritics — i and ī. Under the ī diacritic, he placed some kind of dot (see the picture; sorry for the poor image quality). Could this dot mean that of the two diacritics, the one under which the dot is placed should be considered the correct one? 

I would be grateful for any hints you can give me.

Best regards,

Dmitrii Komissarov