Edible part of mango is :-

Mango is a drupe, a fleshy fruit that develops from a monocarpellary superior ovary and is one-seeded.
Its pericarp has three layers: a thin outer epicarp (skin), a fleshy, juicy middle mesocarp, and a hard, stony inner endocarp that encloses the seed.
The fleshy mesocarp is the part that is eaten.
(In coconut, also a drupe, the mesocarp is fibrous and the endosperm is eaten.)
So the edible part of mango is the mesocarp.