Hi,

Is there any configuration for it ?

No sorry.

Or else how can we do this?

You can do this:
- Set to "No" the parameter "Upload with User Crop & Webcam", now you will see a simple upload field
- With simple upload field the image will be automatically cropped. To prevent this you need to make some changes to our code, in file /administrator/components/com_jsn/helpers/fields/image.php replace at line 151 (main image) and 141 (thumbs) this code:

$foo->image_ratio_crop = true;

with this:

$foo->image_ratio = true;

Now with normal upload (no crop/webcam) the parameter height/width will work as max-height/max-width