Step 1: Draw a circle and mark 8 positions.
Step 2: Use the given information to place the girls.
Lets place Geetha at position 1. Deepa is opposite, so Deepa is at position 5.
Deepa is between Arathi and Farah.
Chaitras right hand neighbour is Geetha, so Chaitra is at position 8.
Esha is to the left of Chaitra (position 7).
Esha is to the right of Arathi (position 6).
So far: Geetha (1), ?, ?, ?, Deepa (5), Arathi (6), Esha (7), Chaitra (8).
Deepa (5) is between Arathi (6) and Farah. This means Farah is at position 4.
The order is Farah (4), Deepa (5), Arathi (6) (clockwise).
Beena enjoys having Hamsa to her left and Farah to her right. If Farah is at 4, Beena is at position 3, and Hamsa is at position 2.
Final arrangement (clockwise from Geetha): Geetha (1), Hamsa (2), Beena (3), Farah (4), Deepa (5), Arathi (6), Esha (7), Chaitra (8).
Step 3: Find the member diagonally opposite to Arathi.
Arathi is at position 6. The person diagonally opposite is at position $6 + 4 = 10 \equiv 2 \pmod{8}$. The person at position 2 is Hamsa.