In my application i have enabled the ARC. But in my application following lines gives me memory leaks according to instruments. It is in ios 7.0.
-(id)init{
My guess right now is that your entire object is leaking, which means that the NSMutableArrays created in -init also leak. The version that calls copy isn't leaking because the copy is probably returning a singleton instance of NSArray (as there are zero elements in it, and it's an immutable NSArray, there's probably a singleton instance for that).