Six girls Tanya, Puja, Richa, Neha, Nisha and Arpita are sitting around a circular table facing the center(not necessarily in the same order). Tanya and Puja are also sitting next to each other. Neha and Nisha are sitting next to each other. Only two girls are sitting between Richa and Tanya. Puja is to the immediate left of Arpita. Neha is not sitting next to Tanya. Who is to the immediate left of Tanya?

Nisha

We arrange the seats step- by- step:

1. Tanya and Puja are also sitting next to each other. Only two girls are sitting between Richa and Tanya. Puja is to the immediate left of Arpita.

⇒ We place Richa at position1 and Tanya at 4. Since Tanya and Puja are sitting next to each other and Puja is to immediate left of Arpita, so Arpita is at position 2 and Puja is at position 3.

2. Neha and Nisha are sitting next to each other. Neha is not sitting next to Tanya. 

⇒ Neha cannot be at position 5, so she is placed at 6. Nisha is therefore, at position 5.

This is the  complete sitting arrangement. 

According to the arrangement, the immediate left of Tanya is Nisha.