Hi kailash, what program are you importing the OBJ into?

Possibly that program decides to combine objects with the same name together on its own, regardless of whether they are separate in the OBJ file or not.

What happens if you import the attached OBJ file that has 3 boxes with the same name in it but as separate objects?

I examined this OBJ file directly with a text editor to 100% verify that there are 3 separate objects in it, each with the same name though.

If your program imports this as only 1 single mesh object then it's doing the combining itself and maybe there is a setting in it that you need to adjust.

- Michael