You should choose KIIT Bhubaneswar for studying Law. It is older and more reputed. On an overall scale, it is better than UPES, Dehradun. Placement will depend on your interest. For Judiciary careers, KIIT Bhubaneswar offers more exposure and opportunities. Few law firms also take part in campus placements. The highest CTC offered in KIIT Bhubaneswar placements is around INR 7 LPA. UPES offers better opportunities in corporate law.
Among the above institutes, KIIT Bhubaneswar is definitely the best choice for law students, considering almost all the factors except the quality of hostels. I will try to give you some idea about both the institute based on what I heard from my friends who attends these two Law School.
Another trying that you should consider while choosing an institute is the distance of your hometown and connectivity. If this is your first time staying away from home, it may be wise to choose an institute nearby. All that being said, do consider the above factors and choose the institute that will provide you enough opportunities to explore what you want.