Both IIT Gandhi and IIT Bhubaneshwar are good . But I would prefer you to choose IIT Gandhinagar. It has an impressive rating of 4.4/5. Though both are IIT's and almost have the same reviews about infrastructure and faculty it is the placements that matter. The college is visited by top companies with a very good package of 20LPA. All the best
Both the IITs are almost comparable and as you have mentioned that you have the same branch choice in both the colleges then it is now more on you into which college you are comfortable studying. According to NIRF ranking IIT Gandhinagar is higher than Bhubaneswar but that difference is not much of difference.
So you could choose Gandhinagar above Bhubaneswar if you want to. Rest is similar in the both IITs.
Hope this helps.