It is suggested to go to Nizam College. Osmania University is a bit stricter, almost like a school. The timings are fixed from 9 to 5. You will have no time for other extra-curricular activities.
In Nizam College, the timing is usually from 9/10 am to 1 pm. This gives you enough time for other activities. It offers a good combination of subjects for the courses, especially for BA.
The syllabus at Nizam College is upgraded every year. This allows you to go through a wide range of books which enhances your all-around development.