Everytime you exports products you have to pay duties to Government of India.
Government uses duties to discourage exports. For example let us say we had bad rainfall and agricultural output comes down. Duties are used to prevent exports of whatever little is produced as this will lead to bigger shortages in India causing price rise or inflation.
Government wants to encourage textle exports not discourage the same. So the duty drawback is the government giving back or refunding duties to a textile exporter the he/ she has already paid. So these drawbacks are here to stay.
So please dont misinterpret the data you see