Is it normal to feel shocks on corner of laptop
That's probably due to current leakage. Current is somehow not flowing through the intended path, so there may be some sort of short circuit or damage from the inside of your laptops.
In that case it could be a grounding problem.
Answers on this forum https://www.quora.com/Why-does-the-case-of-my-laptop-often-give-me-an-electric-shock could be helpful too, though most of them basically repeat what I've already said.