When you book thought the tour agency, they are responsible for tight connections. See NSB on transfer times: https://www.nsb.no/en/our-tickets/transfer-times%281%29
When a journey involves a change of trains, the tranfer time is
defined at a minimum of 30 minutes for NSB Lokaltog (commuter train)
services and 60 minutes for NSB Regiontog (inter-city train) services.
Please take into account train arrivals at airports and flight
check-in times. Specifically, 60/30 minutes extra time must be allowed
for arrival at airports in addition to the airline's check-in time.
For journeys with a shorter transfer time, you are not entitled to a
refund in the event of delay* or service interruption, even if the
journey was booked by using the Travel Planner at nsb.no. You can in
other words not make a claim for reimbursement of expenses for
alternative transportation etc. as a result of a lost connection.