Add coriander leaves, mint leaves, green chilli, ginger, salt, lemon juice, and ice cubes in a mixture jar. Grind it into a thick paste.
Now in a pan, add coriander seeds, cumin seeds, and dry Kashmiri red chilli. roast it on low flame till it is slightly golden brown. Cool down slightly and grind it into a coarse powder. Keep it aside.
Then in a pan, add tamarind, jaggery, and water. Mix well and boil the mixture on the medium-low flame will tamarind becomes soft.
Cool down the tamarind mixture and sieve it in a mixing bowl.
Then in a mixing bowl, add 2.5 cup water, grinded masala, green paste, chaat masala, black salt, dry mango powder, salt, and lemon juice. Mix well.
Add some chopped onion (optional) and mix well.
Refrigerator pani for 2 hrs so masala flavor absorbs in it.
Serve street-style pani with puri and masala.