Sir i am having doubt, how to import the mesh the generated using GAMBIT to PRO-AMM and vice versa. Thanks in advance

with reg Sha

Going from gambit to prostar should be easy. They both read a number of shared formats (nastran, patran, CGNS...). You won't be able to take a pro-am mesh and read it into fluent because fluent can't handle trimmed cell shapes.

IF you want to import Gabmbit mesh to prostar, you can just use "gambit" command.

IF you want to import prostar mesh into Gambit you must use third mesh format like patran, nastran.

As I know, Fluent can read the Trim mesh.

Because fluent can read the mesh which generated by Harpoon.

No-harpoon doesn't create trimmed cells which are basically a subset of polyhedra. Harpoon only creates things that fluent (and prostar) can understand. So if you create a tet or hex mesh in prostar you can export it to fluent. If you create a pro-am trimmed mesh you cannot export that to fluent. Fluent can't do polyhedra.