Hey,
UPSC provides several kind of concessions  to a person with disability. It has several posts reserved for PWD candidates in different services. However, IPS is once such Department that requires one to  physically fit,hence you cannot become an IPS officer. But,there are several other departments equal in rank, where you can serve the nation including the Indian Administrative Service(IAS) or Indian Foreign Service(IFS).
Hope this helps.
Good luck.

Dear candidate

For becoming an IPS officer the physical Constraints matter and also matters is capacity, dedication and sincerity and your performance matters and the physical constraints include Vision, Height, Chest Expansion, Hearing ability and many others because the job of an IPS officer is very complicated.

Hope this Information is Helpful.