Is it possible to use a low resolution camera with low mega pixels and make it look like the video was shoot with a camera with high mega pixel (120 MP to say) after using adobe after effects?
If you're asking whether you can use AE to increase the actual or apparent resolution of a low-res source, the answer is no. You can't create resolution where none exists. If you could, no one would ever spend money on hi-res cameras.
What you can do is 'sharpen' an image, which increases the contrast of edge detail and may increase apparent resolution a little bit. But this doesn't increase actual resolution; it actually reduces it slightly.