Pls let us know trains that you have booked the tickets.
If they are confirmed tickets, then there is no point cancelling the tickets for all 20.
Also, trains hyb to MMR/SNSI reach early in the morning to SNSI, so from my point of view, you may keep the tickets the with you instead of going for cancellation.
If the break journey time at...
more... HYB is a problem, then you may cancel but ensure you get 20 confirm tkts for the vskp/BBS- SNSI train.