Does blender have a UV relax like 3ds max: so it relaxes the entire UV island with the border vertices including ( Minimize stretch doesn't effect the border vertices)?
In 3dsMax the Relax Tool has multiple options to relax the UV mesh: By Face angles, Edge angles and by Centers. And it can also relax the island borders.
Blender lacks these features, and it's relaxation ("Minimize stretch") usually makes things worse (because the border doesn't relax so the stretching from border propagates inside).
Instead what is used in Blender is UV Sculpting (UV > UV Sculpt Q). This brings up a brush with additional options in Tool Shelf panel T:
The default Grab brush can be switched to Smooth brush with HC and Laplacian smooth methods. Also Lock Borders can be turned off to smooth the island borders.
Note that both the smoothing algorithms are not real UV relaxation. They work spatially, not angle-based. The difference is that HC preserves the shape of islands better. After sculpting you should still run Minimize Stretch for best results, that's why it is in blender.
It takes a bit more work but you can get same stretch-less UV map as in Max.