Aachar is the name for pickles of the Indian subcontinent. They are usually made by finely chopping fruit or vegetables and marinating them in brine or edible oil, and seasoning with spices. Some regions use the same technique for meat and fish.
The most common pickles of this style are made from mango and lime, but others are made from a wide variety of ingredients, eg cauliflower, garlic, radish.
These can be homemade or bought commercially.
The Tarla Dalal website has lots of achaar recipes.