Is there a distant restriction to travel by train 12626 kerala express? If yes, what is the minimum distance?

I hope this will help:

"Western Zone Railway has imposed distance restriction on certain long distance and Super fast trains, to restrict short distance passengers from boarding these trains and encroaching upon accommodation earmarked for long distance passengers. However, short distance passengers can be booked in advance on these trains to the extent of intermediate station quota. Ticket checking staff on the station or on the train can allow passengers to travel against vacant accommodation, irrespective of the distance restriction, provided the passenger is holding a journey ticket for or short of the station upto which accommodation is available. Distance restrictions vary from train to train and are applicable to certain section of the journey."

No. Train No. 12626 Kerala Express is a general super fast express train. There is no restriction of distance in this train.

Yes, There are restriction to travel less than 600 KM