Soak the makhana in coconut milk for 30 minutes until soft.
Blend the soaked makhana along with the coconut milk into a smooth, creamy paste.
Soak the chia seeds separately for 15–20 minutes until they become gelatinous.
Add the mango puree to the makhana mixture and blend briefly.
Transfer to a bowl and mix in the soaked chia seeds.
Add jaggery powder as needed and mix well.
Add the mango pieces. Chill and serve cold.