Quote - I am about to make a fashion software but i need realistic models like does created in poser and blender can i import these models into my software?

Yes you can.  I'm also starting to experiment with making clothing for V4, so this is what I did.

First I exported the base V4 model as an OBJ format with all vertices welded so that its a single object when I import it into Blender.  Next I applied some of the various base body morphs such as Amazon, Bodybuilder, Utopian, etc. and exported each of these in the same way.

Second, I import each as its own blend file in Blender and named the file so that it was easy for me to tell which was what morph shape.

Third, I set up a base work file and on the first layer I LINK to the V4 base blend file.  By Linking the mesh is imported but cannoted be directly edited or moved.  This way i don't have to worry about accidentally alterting it or moving it since the only reason I want it there is as a reference for making clothing fits.  Next on other layers I link the other morphed version so that I can later adjust my clothing items to fit each and export fit morphs all from the same blend file.