Based on my experience, I can say VIKALP is the most useless scheme of railway. I saw current booking seats getting disappearing in front of my eyes thinking vikalp would take care of my accomodation, but all it does is assign some leftover seat after current booking (second charting).
So Actually this might be a useful option for someone very lazy to even check for current availability. But if you really want yourself to get a seat in alternate train, just keep checking the current availability and book it manually and then cancel you original ticket. It might cost you cancellation charges but atleast you'll get yourself a confirmed seat.