You need more than 8.8 CGPA to change to Electrical Engineering from Civil Engineering. The required cutoff varies depending on various factors like competition, the number of seats available, etc. But the cutoff stays in the band of 8.8 - 9.5. In case of a tie, the student who had a better JEE Advance rank is given priority.
To change branches in IIT Bhubaneswar you will need more than 8.5 CGPA. Students of IIT Bhubaneswar can change their branch after the second semester(spring semester). The rules for all branches are the same.