Just sharing my experience at BLR on the other way. I was flying to KTM via DEL on AI international coded flights. Immigration was at BLR. The DF staff refused to sell DF stuff and advised me to buy in DEL. They all seem to be confused including AI SATS staff on whether DF purchases are allowed or not. I decided to play safe and didn't press.

On the other hand, my return flight will be domestic from DEL. I am not sure how and where to purchase DF stuff. I would have checked in my baggage to BLR. There is also not enough time. Experts, help!