First chop all the jamuns into small pieces and remove the seeds.
Make a fine puree in a blender and then strain the puree through a strainer to extract any solids.
Take this jamun puree in a pan.
Into that add sugar and mix well.
Turn on heat and allow to boil.
In the meantime, mix agar-agar with 2 tbsp water in a small bowl and allow to bloom.
Add coconut milk into and mix again.
When the jamun sugar mixture comes to a boil, then lower the heat and add the agar-agar and coconut mixture.
Stir well to avoid any lumps formation and then cook for 1-2 minutes more over low-medium heat, stirring in between.
Then turn off heat and allow the mixture to cool down a bit.
Meanwhile grease the serving glass / molds (i have used swirl pans here).
Pour the mixture onto it and then keep aside to cool down completely.
Once cooled, refrigerate the molds overnight or atleast for 2-3 hours to set.
Finally just unmold the jamun coconut panna cotta over serving platter simply. If it is not coming out easily, then just place the molds in warm water for few seconds and then unmold. If using glass, then one can serve as it is or unmolding also.
After unmolding, sprinkle some desscicated coconut or coconut chips and immediately serve !