Kharosthi script was mostly written from right to left in ancient India.

Explanation:
The Kharosthi script was an ancient script used in the Gandhara region (present-day Afghanistan and Pakistan) and was one of the scripts used in ancient India. It was primarily used to write the Gandhari Prakrit language, which was a form of Prakrit that was widely spoken in the region during that time.

The Kharosthi script is unique because it is written from right to left, unlike most other ancient Indian scripts which were written from left to right. This means that the script starts from the right side of the page and progresses towards the left side.

The script consists of a set of characters that represent consonants and vowels. The consonants are written as standalone characters, while the vowels are usually indicated by diacritic marks placed above or below the consonant characters.

The Kharosthi script was derived from the Aramaic script, which was used in ancient Persia. It was adapted to write the local languages of the Gandhara region, including Gandhari Prakrit.

The script was used for a variety of purposes, including writing official documents, religious texts, and inscriptions on coins and other objects. It was also used for writing Sanskrit and other Indic languages in the region.

However, over time, the Kharosthi script fell out of use and was eventually replaced by other scripts, such as the Brahmi script. Today, the script is no longer in common use and is primarily of historical and archaeological interest.

In conclusion, the Kharosthi script of ancient India was mostly written from right to left, setting it apart from other scripts used in the region at that time.