Hello student yes sure you can show the xerox copy of your Adhar Card as an I'd Proof at the examination center of your COMEDK Examination. In I'd proof you can show any of the documents mentioned below -

1)Adhar card

2)Pan card

3)Passport

4)Driving license

For more updates refer to the link mentioned below -

https://engineering.careers360.com/articles/comedk-uget/amp

Feel free to comment if you've any doubt.

Good luck