From statement I: Radhika is to the north of Priyanka who is at the left of Ayesha.
The position of Radhika with respect to Anshula cannot be determined.
From statement II: Anshula is to the south of Ayesha.
The position of Radhika with respect to Anshula cannot be determined.
Combining statement I and II:
Thus, from the above diagram, we can conclude that Radhika is to the north-west of Anshula.
Therefore, data in both statements I and II together are necessary to answer the question.