Dear Anushka,

No, there is no disadvantage to apply for both COMEDK and Uni-gauge. 

There is advantage to apply for both as there is no seperate entrance exam.

Your marks in entrance exam is used for both the colleges. You will receive two score cards which you can use to take admission in both and through Uni-gauge you can take admission in good college which provides good teaching and placements.

To know the colleges in which you can apply through Uni-gauge you can refer below link

Https://www.unigauge.com/comed-k-uget-member-institutions-list/

Good luck!!