can i get duplicate ticket if i lost my book ticket of sleeper class?

if you lost your ticket, you need to buy a replacement ticket and have the booked seat reclaimed at least 20 minutes before check in time at the ticket office in a railway station. After you get on board, you should report your loss and buying a replacement ticket to the conductor, and the conductor will provide you a voucher. Upon arrival at the destination, you can go to the tikcet office of the railway station to refund the cost of the replacement ticket. the documents you need to provide are the replacement ticket, ID certificate or passport, and the voucher.