Note the following and apply.

Exam for both will be held on the same day.

Application will be same for both , you just need to select whether you need only COMEDK or UNI-GAUGE

or both.

Counselling for COMEDK will be held at Bangalore and for UNI-GAUGE with your scorecard you need to apply to individual member universities of ERA foundation.Counselling held separately by individual universities.

You can see more information here 

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

https://engineering.careers360.com/exams/uni-gauge-e

All the best .