I think about the world Railways, in which India is included too. the only double Deck train to have single Sleeper system mostly exists in the Amtraks n the Russian DD's.
Such design is yet to b implemented in Indian Railways with lot of changes.
India is one of the first earliest nations to bring the train_set system in the form of Multiple Unit Train cars, back in its earliest days.
But...
more... IR didn't modify this technology in the coming generations where the world has gone beyond.
JUGAAD or whatever, IR is dead slow in progress, accept or not, that's up-to people.
Only Time n Patience pays off in IR.