Hello cdsm_03
When you travel on a group ticket, on long-distance trains (IC, IR) seats will be reserved for you.
Depending on the size of your group, the entire coach will be reserved.
If you travel on a later connection, the ticket is still valid. But, there won’t be any reserved seats, and you have to find seats yourself. In addition, other travellers (commuters) may get angry because you did not use the train which had seats reserved for you, and you are going to take ‘their’ seats.
Kind regards,
Roland