Answer

In Jain Dharma, the Manglik is traditionally recited in Prakrit, especially Ardhamagadhi Prakrit.

Explanation

Many ancient Jain sutras, mantras, and prayers are in Prakrit because it was the language used for preserving early Jain teachings. The Manglik includes sacred Jain verses such as praises to the Arihantas, Siddhas, Acharyas, Upadhyayas, and Sadhus.

Takeaway

So, Manglik is mainly in Prakrit / Ardhamagadhi Prakrit, not Sanskrit or modern Hindi/Gujarati, though translations and explanations may be given in many languages.