Answer

In Jain practice during Paryushan, chaas/buttermilk is generally avoided by many people, especially when following stricter Paryushan food rules.

So Amul Masti Chaas is best avoided during Paryushan.

Explanation

The main reasons are:

• It is a processed packaged drink, and ingredients/preservatives may not always fit strict Paryushan discipline.
• Chaas is dairy-based, and many Jains reduce or avoid certain dairy preparations during Paryushan depending on family tradition and level of observance.
• Ready-made products may contain additives such as stabilizers, preservatives, spices, or ingredients that may not be suitable for Paryushan niyam.

If your family or Jain sangh follows a more lenient rule and allows fresh homemade chaas, that is different from packaged chaas. But for strict Paryushan observance, packaged Amul Masti Chaas should not be taken.

Takeaway

For Paryushan, it is safer and more spiritually disciplined to avoid Amul Masti Chaas. If unsure, follow your guru, family niyam, or local sangh maryada.