Q.My Matured (10 Years) Coconut Is Now Producing Less Fruits
The coconut plant in my house produces about 4 fruits per bunch even though other coconuts in the same vicinity are producing more fruits, in certain cases 20 or more. What might be the reason?

Certified GKH Gardening Expert
Is the tree really inside your house or do you mean "at my house?" They are not really ideal plants for indoors. Here are some problems with coconut trees in this publication.
https://www.gardeningknowhow.com/edible/fruits/coconut/coconut-tree-problems.htm