I am not able to connect my arduino uno to Computer after my project.

After successfully uploading a program. While running it with components, the Atmega 16U2 starting getting hot. I immediately shut the power. But from then my computer is not able to recognized Arduino UNO connected.
When I connect the board to the computer the power led(green) turns on and the Pin 13 led turns on(do not blink) and Atmega 328p gets hot slightly.
Can anyone help out with this?
Is Atmega 16U2 damaged or Atmega 328p?

A little more detail please like a schematic.
Have you tried removing all connections to the board and then trying an upload ?
If that fails it sounds like you may have fried the board.
That is usually caused by a mistake in wiring.

Could you take a few moments to Learn How To Use The Forum.
Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum in the future.

is the whole board waste now or some component can be replaced

If the board is not recognised, the 16U2 more than likely died; you might have killed more components in the process. If your code was controlling pin 13 and it no longer does, the 328P is probably also dead.