No, there is no kind of ragging in Allahabad University. Being a popular and reputed institution, it has strict rules and protocols set against ragging and serious punishment will be given to those who found practice any kind of such activities inside the campus or hostel.
There may be a formal introduction between you and your seniors but there is nothing to worry about it as they will only ask you to introduce yourself which is a common thing in all colleges and hostels.
You can join AU without any worries with confidence and attend all your classes and make some new friends. You can attend your classes and stay in hostels in comfort with any worries or problems.