Adata 1 TB Hard Disk at Rs.3790, Toshiba Rs.3880, Dell Rs.3990, WD Rs.3949

Amazon:
WD Passport Ultra 2.5 inch 1 TB External Hard Drive Rs.3949
Western Digital 1TB WD Elements Rs. 3979
Seagate Expansion Falcun 1 TB External Hard Disk Rs.4179
Western Digital 1TB WD Elements Rs. 3979
WD Passport Ultra 2.5 inch 1 TB External Hard Drive Rs.3949
Toshiba Canvio Simple 1TB Portable External Hard Drive Rs.3878

Flipkart: ( Additional 10% cashback for Axis bank debit/credit card users)
Toshiba Canvio Simple 1 TB External Hard Disk Rs.3890
Dell Backup Plus 1TB USB 3.0 Rs.3990
Adata HV610 2.5 inch 1 TB External Hard Disk Black Rs.3790 or White Rs. 3790
WD My Passport Ultra 2.5 inch 1 TB External Hard Drive Rs.4170
Transcend StoreJet 25M3 2.5 inch 1 TB External Hard Disk Rs.4190
Adata HV620 2.5 inch 2 TB External Hard Drive Rs.6190