Now 'Vikalp' option appears only after you complete booking process (earlier it was appearing just beneath the 'consider for auto upgradation' option).
When you are through with payment after booking e tickets, the screen to opt for 'Vikalp' pops up & lets you select from a list trains on which alternate accommodation is available.
If you couldn't find any 'Vikalp' option, it only means alternate accommodation is not available in any of the trains connecting your source & destination.