Shape appears different in edit mode, object mode and render I'm trying to animate a figure to jump and the animation runs fine when I play it in timeline but when I render image/animation, it also shows the initial T-pose figure that I started with:

what i found is that in the edit mode the shape of the figure is still in the initial t-pose and the armature seems disconnected from the object
in edit mode:

whereas in the object mode the armature and body are connected and not in t-pose
in object mode:

is it because I had not applied the armature modifier before making the animation?
It is because you have a duplicate of your object in you scene. The one  named tpose_human_body. I see you have it hidden but blender still renders it. If you want it to not be rendered move it into a new collection and disable the collection from the view layer by unchecking the tickbox near it.
There was a simpler way to disable render for objects before but it has changed and nI don't know how to do it in 2.8