Hi Varun,
You
cannot really disable the F12 on the client side.
What you can do is
capture the key press event and handle that event when F12 was the pressed key (you could also check which browser type it is using Javascript [you specifically specified IE]), but it can easily be bypassed by clever users, so it's not a strong solution.
Another approach - You could (to some extent) "hide" your real Javascript by using
Obfuscation [
^]
Best,
H