Thank you for posting on this platform. I understand preparing for UPSC is tough and you have to be completely prepared.
The posting is for you to decide, as you will be the one attempting the exam. I suggest you do your research on IAS and IPS postings, the roles and responsibilities which comes with each post, the subjects you need to be prepared for and lastly, see which post interests you the most.
Each post has its own share of roles and responsibilities. It is important to know and understand what they entail, as it makes the choice easier.
Both are equally prestigious posts and I wish you all the best for the exams.